diff --git a/app/reanimate-example.hs b/app/reanimate-example.hs
--- a/app/reanimate-example.hs
+++ b/app/reanimate-example.hs
@@ -1,36 +1,32 @@
 #!/usr/bin/env stack
 -- stack runghc --package reanimate
 
-{- | reanimate example
-
-To run this example:
-
-stack runghc --package reanimate app/reanimate-example.hs
-
-and wait for the browser to open ...
-
--}
+{-# LANGUAGE MonoLocalBinds #-}
+{-# LANGUAGE NegativeLiterals #-}
 {-# LANGUAGE OverloadedLabels #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE NoImplicitPrelude #-}
-{-# LANGUAGE NegativeLiterals #-}
-{-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE MonoLocalBinds #-}
 
+-- | reanimate example
+--
+-- To run this example:
+--
+-- stack runghc --package reanimate app/reanimate-example.hs
+--
+-- and wait for the browser to open ...
 module Main where
 
 import Chart
 import Chart.Examples
+import Chart.Reanimate
 import Control.Lens hiding (transform)
 import NumHask.Prelude hiding (fold)
-import Chart.Reanimate
 import Reanimate as Re
 
 main :: IO ()
 main =
-  -- reanimChartSvg defaultReanimateConfig (sOpac lineExample)
   reanimate $
-  foldl' seqA (pause 0) $ (applyE (overBeginning 1 fadeInE) . applyE (overEnding 1 fadeOutE)) . mapA pathify . (\cs -> animChartSvg defaultReanimateConfig (const cs)) . (#hudOptions %~ colourHudOptions light) <$> examples
+    foldl' seqA (pause 0) $ (applyE (overBeginning 1 fadeInE) . applyE (overEnding 1 fadeOutE)) . mapA pathify . (\cs -> animChartSvg defaultReanimateConfig (const cs)) . (#hudOptions %~ colourHudOptions light) <$> examples
 
 examples :: [ChartSvg]
 examples =
@@ -59,18 +55,3 @@
     vennExample,
     arrowExample
   ]
-
-sOpac :: ChartSvg -> Double -> ChartSvg
-sOpac cs o =
-  scaleOpacChartSvg (Range 0 1) o .
-  (#hudOptions %~ colourHudOptions light) $
-  cs
-
-scaleOpacChartSvg :: Range Double -> Double -> ChartSvg -> ChartSvg
-scaleOpacChartSvg r x cs =
-  cs &
-  #hudOptions .~ scaleOpacHudOptions (cs & view #hudOptions) (project (Range zero one) r x) &
-  #chartList .~
-  ((#annotation %~ scaleOpacAnn (project (Range zero one) r x)) <$>
-    view #chartList cs)
-
diff --git a/chart-svg.cabal b/chart-svg.cabal
--- a/chart-svg.cabal
+++ b/chart-svg.cabal
@@ -1,6 +1,6 @@
 cabal-version:  2.4
 name:           chart-svg
-version:        0.2.1
+version:        0.2.2
 synopsis:       Charting library targetting SVGs.
 description:
     This package provides a charting library targetting SVG as the rendered output.
@@ -8,15 +8,15 @@
     == Usage
     .
     >>> import Chart
-    >>>
-    >>> let xs = [[(0.0, 1.0), (1.0, 1.0), (2.0, 5.0)], [(0.0, 0.0), (3.0, 3.0)], [(0.5, 4.0), (0.5, 0)]] :: [[(Double, Double)]]
-    >>> let ls = fmap (PointXY . uncurry Point) <$> xs
-    >>> let anns = zipWith (\w c -> LineA (LineStyle w c Nothing Nothing Nothing Nothing)) [0.015, 0.03, 0.01] palette1
-    >>> let lineChart = zipWith Chart anns ls
-    >>> writeChartSvgHud "other/lineshud.svg" lineChart
+    >>> :set -XOverloadedLabels
+    >>>let xs = fmap (fmap (uncurry Point)) [[(0.0, 1.0), (1.0, 1.0), (2.0, 5.0)], [(0.0, 0.0), (3.2, 3.0)], [(0.5, 4.0), (0.5, 0)]] :: [[Point Double]]
+    >>> let anns = zipWith (\w c -> LineA (LineStyle w c Nothing Nothing Nothing Nothing)) [0.015, 0.03, 0.01] palette1_
+    >>> let lineExample = mempty & (#chartList .~ zipWith Chart anns (fmap (fmap PointXY) xs)) & #hudOptions .~ defaultHudOptions & #svgOptions .~ defaultSvgOptions :: ChartSvg
     .
-    ![main example](docs/other/lineshud.svg)
+    > writeChartSvg "other/line.svg" lineExample
     .
+    ![main example](docs/other/lines.svg)
+    .
     See "Chart" for a broad overview of concepts, and "Chart.Examples" for a variety of practical examples.
 
 category:       charts
@@ -55,6 +55,7 @@
     JuicyPixels >= 3.3 && < 3.4,
     attoparsec >= 0.13 && < 0.14,
     base >=4.7 && <5,
+    containers >= 0.6 && < 0.7,
     cubicbezier >= 0.6 && < 0.7,
     foldl >= 1.4 && < 1.5,
     generic-lens >= 1.2 && < 3.0,
diff --git a/src/Chart.hs b/src/Chart.hs
--- a/src/Chart.hs
+++ b/src/Chart.hs
@@ -4,10 +4,12 @@
 -- | A haskell Charting library targetting SVGs
 module Chart
   ( -- * Usage
+
     --
     -- $setup
 
     -- * Overview
+
     --
     -- $overview
 
@@ -190,7 +192,7 @@
 --
 -- and an Annotation to describe representation of this data; three line styles with different colors and widths:
 --
--- >>> let anns = zipWith (\w c -> LineA (LineStyle w c Nothing Nothing Nothing Nothing)) [0.015, 0.03, 0.01] palette1
+-- >>> let anns = zipWith (\w c -> LineA (LineStyle w c Nothing Nothing Nothing Nothing)) [0.015, 0.03, 0.01] palette1_
 --
 -- and this is enough to create a Chart.
 --
@@ -198,25 +200,9 @@
 -- >>> :t lineExample
 -- lineExample :: ChartSvg
 --
--- Most charts will, in reality, be a list of charts such as this, and much of the library API is designed for this.
---
--- > writeChartSvg "other/lines.svg" lineExample
---
--- ![lines example](other/lines.svg)
---
--- chart-svg takes inspiration from gaming heads-up display aesthetics. Chart decorations such as titles and axes are tools to interpret the landscape of data being viewed. They should be readily transparent, have sane defaults but be fully configurable.
---
--- The library considers a hud to be a recipe for the creation of a 'Chart' list, but with the physical, on-the-page representation of the data in mind.
---
--- Here is the line chart presented with default hud options.
---
--- > writeChartSvgHud "other/lineshud.svg" lineChart
---
--- ![hud example](other/lineshud.svg)
---
--- 'Hud' creation is a process of integrating the data domain and the physical representation. In the chart above, for example, the axis placement takes into account the physical attributes of the thick blue line which extends slightly beyond the abstract data range. The data area (the canvas) has also been extended so that a tick value (3.5 on the x-axis) can be included.
+-- > writeChartSvg "other/line.svg" lineExample
 --
--- Beyond this, there is nothing special about hud elements such as tick marks and titles, axes. Once they are created (with 'runHudWith') they themselves become charts.
+-- ![lines example](other/line.svg)
 --
 
 -- $hud
@@ -236,4 +222,4 @@
 -- This process is encapsulated in 'runHud'.
 --
 -- An important quality of 'runHud' (and conversion of charts to svg in general)is that this is the point at which the 'XY's of the chart are converted from the data domain to the page domain. Once the hud and the chart has been integrated there is no going back and the original data is forgotten. This is an opinionated aspect of chart-svg. A counter-example is d3 which stores the raw data in the svg element it represents.
-
+--
diff --git a/src/Chart/Bar.hs b/src/Chart/Bar.hs
--- a/src/Chart/Bar.hs
+++ b/src/Chart/Bar.hs
@@ -19,6 +19,7 @@
 where
 
 import Chart.Types
+import Chart.Render
 import Control.Lens
 import Data.Colour
 import Data.FormatN
@@ -39,25 +40,24 @@
 -- | Typical bar chart options.
 --
 -- >>> let barDataExample = BarData [[1, 2, 3, 5, 8, 0, -2, 11, 2, 1], [1 .. 10]] (Just (("row " <>) . pack . show <$> [1 .. 11])) (Just (("column " <>) . pack . show <$> [1 .. 2]))
--- >>> let (ho, cs) = barChart defaultBarOptions barDataExample
+-- >>> let barExample = barChart defaultBarOptions barDataExample
 --
--- > writeChartSvg "other/bar.svg" (ChartSvg defaultSvgOptions ho [] cs)
+-- > writeChartSvg "other/bar.svg" barExample
 --
 -- ![bar chart example](other/bar.svg)
-data BarOptions
-  = BarOptions
-      { barRectStyles :: [RectStyle],
-        barTextStyles :: [TextStyle],
-        outerGap :: Double,
-        innerGap :: Double,
-        textGap :: Double,
-        textGapNegative :: Double,
-        displayValues :: Bool,
-        valueFormatN :: FormatN,
-        accumulateValues :: Bool,
-        barOrientation :: Orientation,
-        barHudOptions :: HudOptions
-      }
+data BarOptions = BarOptions
+  { barRectStyles :: [RectStyle],
+    barTextStyles :: [TextStyle],
+    outerGap :: Double,
+    innerGap :: Double,
+    textGap :: Double,
+    textGapNegative :: Double,
+    displayValues :: Bool,
+    valueFormatN :: FormatN,
+    accumulateValues :: Bool,
+    barOrientation :: Orientation,
+    barHudOptions :: HudOptions
+  }
   deriving (Show, Eq, Generic)
 
 -- | The official bar options.
@@ -93,8 +93,8 @@
              )
     )
   where
-    gs = (\x -> RectStyle 0.002 x x) <$> palette1
-    ts = (\x -> defaultTextStyle & #color .~ x & #size .~ 0.04) <$> palette1
+    gs = (\x -> RectStyle 0.002 x x) <$> palette1_
+    ts = (\x -> defaultTextStyle & #color .~ x & #size .~ 0.04) <$> palette1_
 
 -- | imagine a dataframe you get in other languages:
 --
@@ -103,12 +103,11 @@
 -- - maybe some row names
 --
 -- - maybe some column names
-data BarData
-  = BarData
-      { barData :: [[Double]],
-        barRowLabels :: Maybe [Text],
-        barColumnLabels :: Maybe [Text]
-      }
+data BarData = BarData
+  { barData :: [[Double]],
+    barRowLabels :: Maybe [Text],
+    barColumnLabels :: Maybe [Text]
+  }
   deriving (Show, Eq, Generic)
 
 -- | Convert BarData to rectangles
@@ -191,8 +190,9 @@
   | isNothing (bd ^. #barRowLabels) =
     TickLabels $ pack . show <$> [0 .. (maxRows (bd ^. #barData) - 1)]
   | otherwise =
-    TickLabels $ take (maxRows (bd ^. #barData)) $
-      fromMaybe [] (bd ^. #barRowLabels) <> repeat ""
+    TickLabels $
+      take (maxRows (bd ^. #barData)) $
+        fromMaybe [] (bd ^. #barRowLabels) <> repeat ""
 
 tickFirstAxis :: BarData -> [AxisOptions] -> [AxisOptions]
 tickFirstAxis _ [] = []
@@ -205,14 +205,16 @@
   | isNothing (bd ^. #barColumnLabels) = []
   | otherwise = zip (RectA <$> bo ^. #barRectStyles) $ take (length (bd ^. #barData)) $ fromMaybe [] (bd ^. #barColumnLabels) <> repeat ""
 
--- | A bar chart with hud trimmings.
+-- | A bar chart.
 --
 -- By convention only, the first axis (if any) is the bar axis.
-barChart :: BarOptions -> BarData -> (HudOptions, [Chart Double])
+barChart :: BarOptions -> BarData -> ChartSvg
 barChart bo bd =
-  ( bo ^. #barHudOptions & #hudLegend %~ fmap (second (const (barLegend bd bo))) & #hudAxes %~ tickFirstAxis bd . flipAllAxes (barOrientation bo),
-    bars bo bd <> bool [] (barTextCharts bo bd) (bo ^. #displayValues)
-  )
+  mempty &
+  #hudOptions .~ bo ^. #barHudOptions &
+  #hudOptions . #hudLegend %~ fmap (second (const (barLegend bd bo))) &
+  #hudOptions . #hudAxes %~ tickFirstAxis bd . flipAllAxes (barOrientation bo) &
+  #chartList .~ bars bo bd <> bool [] (barTextCharts bo bd) (bo ^. #displayValues)
 
 flipAllAxes :: Orientation -> [AxisOptions] -> [AxisOptions]
 flipAllAxes o = fmap (bool id flipAxis (o == Vert))
diff --git a/src/Chart/Examples.hs b/src/Chart/Examples.hs
--- a/src/Chart/Examples.hs
+++ b/src/Chart/Examples.hs
@@ -1,7 +1,7 @@
+{-# LANGUAGE NegativeLiterals #-}
 {-# LANGUAGE OverloadedLabels #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RebindableSyntax #-}
-{-# LANGUAGE NegativeLiterals #-}
 {-# OPTIONS_GHC -Wall #-}
 {-# OPTIONS_GHC -fno-warn-name-shadowing #-}
 {-# OPTIONS_GHC -fno-warn-type-defaults #-}
@@ -15,7 +15,6 @@
     textExample,
     glyphsExample,
     lineExample,
-    barDataExample,
     barExample,
     waveExample,
     lglyphExample,
@@ -40,7 +39,6 @@
 
 import Chart
 import Control.Lens
-import qualified Data.List as List
 import qualified Data.Text as Text
 import NumHask.Prelude hiding (lines)
 
@@ -85,8 +83,8 @@
 
 ropts :: [RectStyle]
 ropts =
-  [ blob (palette1 List.!! 1),
-    blob (palette1 List.!! 2)
+  [ blob (palette1 1),
+    blob (palette1 2)
   ]
 
 -- | line example
@@ -103,7 +101,7 @@
 -- >>> xs
 -- [[Point 0.0 1.0,Point 1.0 1.0,Point 2.0 5.0],[Point 0.0 0.0,Point 3.2 3.0],[Point 0.5 4.0,Point 0.5 0.0]]
 --
--- >>> let anns = zipWith (\w c -> LineA (defaultLineStyle & #width .~ w & #color .~ c)) [0.015, 0.03, 0.01] palette1
+-- >>> let anns = zipWith (\w c -> LineA (defaultLineStyle & #width .~ w & #color .~ c)) [0.015, 0.03, 0.01] palette1_
 -- >>> anns
 -- [LineA (LineStyle {width = 1.5e-2, color = Colour 0.69 0.35 0.16 1.00, linecap = Nothing, linejoin = Nothing, dasharray = Nothing, dashoffset = Nothing}),LineA (LineStyle {width = 3.0e-2, color = Colour 0.65 0.81 0.89 1.00, linecap = Nothing, linejoin = Nothing, dasharray = Nothing, dashoffset = Nothing}),LineA (LineStyle {width = 1.0e-2, color = Colour 0.12 0.47 0.71 1.00, linecap = Nothing, linejoin = Nothing, dasharray = Nothing, dashoffset = Nothing})]
 --
@@ -117,12 +115,13 @@
 lineExample :: ChartSvg
 lineExample =
   mempty
-    & #svgOptions . #chartAspect .~ CanvasAspect 1.5
+    & #svgOptions . #chartAspect
+    .~ CanvasAspect 1.5
     & #hudOptions
     .~ exampleLineHudOptions
-           "Line Chart"
-           (Just "An example from chart-svg")
-           (Just (defaultLegendOptions, zip (LineA <$> lopts) ["hockey", "line", "vertical"]))
+      "Line Chart"
+      (Just "An example from chart-svg")
+      (Just (defaultLegendOptions, zip (LineA <$> lopts) ["hockey", "line", "vertical"]))
     & #chartList
     .~ zipWith (\s d -> Chart (LineA s) (fmap PointXY d)) lopts ls
 
@@ -136,9 +135,9 @@
 
 lopts :: [LineStyle]
 lopts =
-  [ defaultLineStyle & #color .~ (palette1 List.!! 0) & #width .~ 0.015,
-    defaultLineStyle & #color .~ (palette1 List.!! 1) & #width .~ 0.03,
-    defaultLineStyle & #color .~ (palette1 List.!! 2) & #width .~ 0.01
+  [ defaultLineStyle & #color .~ palette1 0 & #width .~ 0.015,
+    defaultLineStyle & #color .~ palette1 1 & #width .~ 0.03,
+    defaultLineStyle & #color .~ palette1 2 & #width .~ 0.01
   ]
 
 exampleLineHudOptions :: Text -> Maybe Text -> Maybe (LegendOptions, [(Annotation, Text)]) -> HudOptions
@@ -169,7 +168,7 @@
 textExample =
   mempty & #chartList
     .~ zipWith
-      Chart 
+      Chart
       (TextA (defaultTextStyle & (#color .~ dark) & (#size .~ (0.05 :: Double))) . (: []) . fst <$> ts)
       ((: []) . PointXY . snd <$> ts)
   where
@@ -184,9 +183,10 @@
 -- ![glyphs example](other/glyphs.svg)
 glyphsExample :: ChartSvg
 glyphsExample =
-  mempty &
-  #svgOptions . #svgHeight .~ 50 &
-  #chartList
+  mempty
+    & #svgOptions . #svgHeight
+    .~ 50
+      & #chartList
     .~ zipWith
       ( \(sh, bs) p ->
           Chart
@@ -216,20 +216,18 @@
 barDataExample =
   BarData
     [[1, 2, 3, 5, 8, 0, -2, 11, 2, 1], [1 .. 10]]
-    (Just (("row " <>) . pack . show <$> ([1 .. 11]::[Int])))
-    (Just (("column " <>) . pack . show <$> ([1 .. 2]::[Int])))
+    (Just (("row " <>) . pack . show <$> ([1 .. 11] :: [Int])))
+    (Just (("column " <>) . pack . show <$> ([1 .. 2] :: [Int])))
 
 -- | Bar chart example.
 --
 -- ![bar example](other/bar.svg)
 barExample :: ChartSvg
-barExample = mempty & #hudOptions .~ hc & #chartList .~ cs
-  where
-    (hc, cs) = barChart defaultBarOptions barDataExample
+barExample = barChart defaultBarOptions barDataExample
 
 -- | A reminder that Text scale is at representation level, and so doesn't scale compared with other chart elements, such as a rectangle.
 --
--- ![text local example](other/textlocal.svg) 
+-- ![text local example](other/textlocal.svg)
 textLocalExample :: ChartSvg
 textLocalExample =
   mempty & #chartList
@@ -267,7 +265,7 @@
           . (#size .~ 0.08)
           $ defaultGlyphStyle
     )
-    palette1
+    palette1_
     [EllipseGlyph 1.5, SquareGlyph, CircleGlyph]
 
 -- | Glyph + Lines
@@ -309,7 +307,7 @@
                 ( defaultGlyphStyle
                     & #size .~ 0.01
                     & #borderSize .~ 0
-                    & #color .~ palette1 List.!! 2
+                    & #color .~ palette1 2
                 )
             )
             (PointXY <$> [d])
@@ -328,7 +326,7 @@
 labelExample :: ChartSvg
 labelExample =
   mempty & #chartList
-    .~ [Chart (TextA (defaultTextStyle & #rotation ?~ -pi/4) ["text at (1,1) rotated by -(pi/4) radians"]) [PointXY (Point 1.0 1.0)]]
+    .~ [Chart (TextA (defaultTextStyle & #rotation ?~ - pi / 4) ["text at (1,1) rotated by -(pi/4) radians"]) [PointXY (Point 1.0 1.0)]]
 
 -- | legend test
 --
@@ -367,10 +365,10 @@
 -- ![venn diagram](other/venn.svg)
 vennExample :: ChartSvg
 vennExample =
-  mempty &
-  #chartList .~ zipWith (\c x -> Chart (PathA (defaultPathStyle & #color .~ setOpac 0.2 c) (fst <$> x)) (PointXY . snd <$> x)) palette1 (toPathXYs . parsePath <$> vennSegs) &
-  #svgOptions .~ (defaultSvgOptions & #chartAspect .~ FixedAspect 1) &
-  #hudOptions .~ defaultHudOptions
+  mempty
+    & #chartList .~ zipWith (\c x -> Chart (PathA (defaultPathStyle & #color .~ setOpac 0.2 c) (fst <$> x)) (PointXY . snd <$> x)) palette1_ (toPathXYs . parsePath <$> vennSegs)
+    & #svgOptions .~ (defaultSvgOptions & #chartAspect .~ FixedAspect 1)
+    & #hudOptions .~ defaultHudOptions
 
 {-
 These were originally based on:
@@ -386,36 +384,36 @@
 -}
 vennSegs :: [Text]
 vennSegs =
-      [ "M0.0,-1.2320508075688774 A0.5 0.5 0.0 1 1 1.0,0.5 1.0 1.0 0.0 0 0 0.5,-0.3660254037844387 1.0 1.0 0.0 0 0 0.0,-1.2320508075688774 Z",
-        "M-1.0,0.5 A0.5 0.5 0.0 1 0 1.0,0.5 1.0 1.0 0.0 0 1 0.0,0.5 1.0 1.0 0.0 0 1 -1.0,0.5 Z",
-        "M-1.0,0.5 A0.5 0.5 0.0 1 1 0.0,-1.2320508075688774 1.0 1.0 0.0 0 0 -0.5,-0.3660254037844387 1.0 1.0 0.0 0 0 -1.0,0.5 Z",
-        "M0.5,-0.3660254037844387 A1.0 1.0 0.0 0 1 1.0,0.5 1.0 1.0 0.0 0 1 0.0,0.5 1.0 1.0 0.0 0 0 0.5,-0.3660254037844387 Z",
-        "M0.0,0.5 A1.0 1.0 0.0 0 1 -1.0,0.5 1.0 1.0 0.0 0 1 -0.5,-0.3660254037844387 1.0 1.0 0.0 0 0 0.0,0.5 Z",
-        "M0.0,-1.2320508075688774 A1.0 1.0 0.0 0 1 0.5,-0.3660254037844387 1.0 1.0 0.0 0 0 -0.5,-0.3660254037844387 1.0 1.0 0.0 0 1 0.0,-1.2320508075688774 Z",
-        "M0.5,-0.3660254037844387 A1.0 1.0 0.0 0 1 0.0,0.5 1.0 1.0 0.0 0 1 -0.5,-0.3660254037844387 1.0 1.0 0.0 0 1 0.5,-0.3660254037844387 Z"
-      ]
+  [ "M0.0,-1.2320508075688774 A0.5 0.5 0.0 1 1 1.0,0.5 1.0 1.0 0.0 0 0 0.5,-0.3660254037844387 1.0 1.0 0.0 0 0 0.0,-1.2320508075688774 Z",
+    "M-1.0,0.5 A0.5 0.5 0.0 1 0 1.0,0.5 1.0 1.0 0.0 0 1 0.0,0.5 1.0 1.0 0.0 0 1 -1.0,0.5 Z",
+    "M-1.0,0.5 A0.5 0.5 0.0 1 1 0.0,-1.2320508075688774 1.0 1.0 0.0 0 0 -0.5,-0.3660254037844387 1.0 1.0 0.0 0 0 -1.0,0.5 Z",
+    "M0.5,-0.3660254037844387 A1.0 1.0 0.0 0 1 1.0,0.5 1.0 1.0 0.0 0 1 0.0,0.5 1.0 1.0 0.0 0 0 0.5,-0.3660254037844387 Z",
+    "M0.0,0.5 A1.0 1.0 0.0 0 1 -1.0,0.5 1.0 1.0 0.0 0 1 -0.5,-0.3660254037844387 1.0 1.0 0.0 0 0 0.0,0.5 Z",
+    "M0.0,-1.2320508075688774 A1.0 1.0 0.0 0 1 0.5,-0.3660254037844387 1.0 1.0 0.0 0 0 -0.5,-0.3660254037844387 1.0 1.0 0.0 0 1 0.0,-1.2320508075688774 Z",
+    "M0.5,-0.3660254037844387 A1.0 1.0 0.0 0 1 0.0,0.5 1.0 1.0 0.0 0 1 -0.5,-0.3660254037844387 1.0 1.0 0.0 0 1 0.5,-0.3660254037844387 Z"
+  ]
 
 -- | Compound path example.
 --
 -- ![path test](other/path.svg)
 pathExample :: ChartSvg
 pathExample =
-  mempty &
-   #chartList .~ [path', c0] &
-   #hudOptions .~ defaultHudOptions &
-   #svgOptions %~
-   ((#outerPad ?~ 0.1) .
-    (#chartAspect .~ ChartAspect))
+  mempty
+    & #chartList .~ [path', c0]
+    & #hudOptions .~ defaultHudOptions
+    & #svgOptions
+    %~ ( (#outerPad ?~ 0.1)
+           . (#chartAspect .~ ChartAspect)
+       )
   where
     ps =
-      [
-        (StartI, Point 0 0),
+      [ (StartI, Point 0 0),
         (LineI, Point 1 0),
         (CubicI (Point 0.2 0) (Point 0.25 1), Point 1 1),
         (QuadI (Point -1 2), Point 0 1),
-        (ArcI (ArcInfo (Point 1 1) (-pi/6) False False), Point 0 0)
+        (ArcI (ArcInfo (Point 1 1) (- pi / 6) False False), Point 0 0)
       ]
-    path' = Chart (PathA (defaultPathStyle & #color .~ setOpac 0.1 (palette1 List.!! 2) & #borderColor .~ Colour 0.2 0.8 0.4 0.3) (fst <$> ps)) (PointXY . snd <$> ps)
+    path' = Chart (PathA (defaultPathStyle & #color .~ setOpac 0.1 (palette1 2) & #borderColor .~ Colour 0.2 0.8 0.4 0.3) (fst <$> ps)) (PointXY . snd <$> ps)
     c0 = Chart (GlyphA defaultGlyphStyle) (PointXY . snd <$> ps)
 
 -- | ellipse example
@@ -423,41 +421,37 @@
 -- (ArcPosition (Point 1 0) (Point 0 1) (ArcInfo (Point 1.5 1) 0 True True))
 --
 -- ![ellipse example](other/ellipse.svg)
---
 ellipseExample :: ChartSvg
 ellipseExample =
-  mempty &
-   #chartList .~ [ell, ellFull, c0, bbox, xradii, yradii] &
-   #hudOptions .~ defaultHudOptions &
-   #svgOptions %~ ((#outerPad .~ Nothing) . (#chartAspect .~ UnadjustedAspect))
+  mempty
+    & #chartList .~ [ell, ellFull, c0, bbox, xradii, yradii]
+    & #hudOptions .~ defaultHudOptions
+    & #svgOptions %~ ((#outerPad .~ Nothing) . (#chartAspect .~ UnadjustedAspect))
   where
-    p@(ArcPosition p1 p2 _) = ArcPosition (Point 1 0) (Point 0 1) (ArcInfo (Point 1.5 1) (pi/3) True True)
+    p@(ArcPosition p1 p2 _) = ArcPosition (Point 1 0) (Point 0 1) (ArcInfo (Point 1.5 1) (pi / 3) True True)
     (ArcCentroid c r phi' ang0 angd) = arcCentroid p
-    ellFull = Chart (LineA $ defaultLineStyle & #width .~ 0.002 & #color .~ (palette1 List.!! 1)) (PointXY . ellipse c r phi' . (\x -> 2 * pi * x / 100.0) <$> [0..100])
-    ell = Chart (LineA $ defaultLineStyle & #width .~ 0.002 & #color .~ (palette1 List.!! 1)) (PointXY . ellipse c r phi' . (\x -> ang0 + angd * x / 100.0) <$> [0..100])
-    c0 = Chart (GlyphA defaultGlyphStyle) (PointXY <$> [c,p1,p2])
+    ellFull = Chart (LineA $ defaultLineStyle & #width .~ 0.002 & #color .~ palette1 1) (PointXY . ellipse c r phi' . (\x -> 2 * pi * x / 100.0) <$> [0 .. 100])
+    ell = Chart (LineA $ defaultLineStyle & #width .~ 0.002 & #color .~ palette1 1) (PointXY . ellipse c r phi' . (\x -> ang0 + angd * x / 100.0) <$> [0 .. 100])
+    c0 = Chart (GlyphA defaultGlyphStyle) (PointXY <$> [c, p1, p2])
     bbox = Chart (RectA $ defaultRectStyle & #borderSize .~ 0.002 & #color .~ Colour 0.4 0.4 0.8 0.1 & #borderColor .~ Colour 0.5 0.5 0.5 1) [RectXY (arcBox p)]
     xradii = Chart (LineA $ defaultLineStyle & #color .~ Colour 0.9 0.2 0.02 1 & #width .~ 0.005 & #dasharray .~ Just [0.03, 0.01] & #linecap .~ Just LineCapRound) (PointXY <$> [ellipse c r phi' 0, ellipse c r phi' pi])
-    yradii = Chart (LineA $ defaultLineStyle & #color .~ Colour 0.9 0.9 0.02 1 & #width .~ 0.005 & #dasharray .~ Just [0.03, 0.01] & #linecap .~ Just LineCapRound) (PointXY <$> [ellipse c r phi' (pi/2), ellipse c r phi' (3/2*pi)])
+    yradii = Chart (LineA $ defaultLineStyle & #color .~ Colour 0.9 0.9 0.02 1 & #width .~ 0.005 & #dasharray .~ Just [0.03, 0.01] & #linecap .~ Just LineCapRound) (PointXY <$> [ellipse c r phi' (pi / 2), ellipse c r phi' (3 / 2 * pi)])
 
 -- | arc example
 --
 -- ![arc example](other/arc.svg)
---
--- There is a bug for rotated ellipses. See 'problematic2' for scaling issue when phi is non-zero.
---
 arcExample :: ChartSvg
 arcExample =
-  mempty &
-   #chartList .~ [arc, ell, c0, bbox] &
-   #hudOptions .~ defaultHudOptions &
-   #svgOptions %~ ((#outerPad .~ Nothing) . (#chartAspect .~ FixedAspect 1))
+  mempty
+    & #chartList .~ [arc, ell, c0, bbox]
+    & #hudOptions .~ defaultHudOptions
+    & #svgOptions %~ ((#outerPad .~ Nothing) . (#chartAspect .~ FixedAspect 1))
   where
     p1 = ArcPosition (Point 1.0 0.0) (Point 0.0 1.0) (ArcInfo (Point 1.0 0.5) 0 False True)
     ps = singletonArc p1
     (ArcCentroid c r phi' ang0 angd) = arcCentroid p1
-    arc = Chart (PathA (defaultPathStyle & #color .~ setOpac 0.1 (palette1 List.!! 2) & #borderColor .~ transparent) (fst <$> ps)) (PointXY . snd <$> ps)
-    ell = Chart (LineA $ defaultLineStyle & #width .~ 0.002 & #color .~ (palette1 List.!! 1)) (PointXY . ellipse c r phi' . (\x -> ang0 + angd * x / 100.0) <$> [0..100])
+    arc = Chart (PathA (defaultPathStyle & #color .~ setOpac 0.1 (palette1 2) & #borderColor .~ transparent) (fst <$> ps)) (PointXY . snd <$> ps)
+    ell = Chart (LineA $ defaultLineStyle & #width .~ 0.002 & #color .~ palette1 1) (PointXY . ellipse c r phi' . (\x -> ang0 + angd * x / 100.0) <$> [0 .. 100])
     c0 = Chart (GlyphA defaultGlyphStyle) [PointXY c]
     bbox = Chart (RectA $ defaultRectStyle & #borderSize .~ 0.002 & #color .~ Colour 0.4 0.4 0.8 0.1 & #borderColor .~ Colour 0.5 0.5 0.5 1) [RectXY (arcBox p1)]
 
@@ -466,67 +460,79 @@
 -- ![arc flags example](other/arcflags.svg)
 arcFlagsExample :: ChartSvg
 arcFlagsExample =
-  mempty &
-   #chartList .~
-     vert 0.02
-     [hori 0.02
-       [ [Chart BlankA [R -0.4 0.4 -1 5],
-          Chart (TextA (defaultTextStyle & #size .~ 0.6 & #rotation .~ Just (pi/2)) ["Sweep"]) [P 0.1 2]],
-         vert 0.02
-         [[Chart BlankA [R -0.25 0.25 -1 2],
-           Chart (TextA (defaultTextStyle & #size .~ 0.4 & #rotation .~ Just (pi/2)) ["True"]) [P 0.1 0.5]],
-          [Chart BlankA [R -0.25 0.25 -1 2],
-           Chart (TextA (defaultTextStyle & #size .~ 0.4 & #rotation .~ Just (pi/2)) ["False"]) [P 0.1 0.5]]
-       ],
-         vert 0.02
-         [checkFlags False True (setOpac 0.3 dark) & view #chartList,
-          checkFlags False False (setOpac 0.3 dark) & view #chartList,
-          [Chart BlankA [R -1 2 -0.25 0.25],
-           Chart (TextA (defaultTextStyle & #size .~ 0.4) ["False"]) [P 0.5 -0.1]]
-         ],
-         vert 0.02
-         [checkFlags True True (setOpac 0.3 dark) & view #chartList,
-          checkFlags True False (setOpac 0.3 dark) & view #chartList,
-           [Chart BlankA [R -1 2 -0.25 0.25],
-            Chart (TextA (defaultTextStyle & #size .~ 0.4) ["True"]) [P 0.5 -0.1]]
-         ]
-       ],
-      [ Chart BlankA [R 0 9 -2.75 -3.25],
-        Chart (TextA (defaultTextStyle & #size .~ 0.6) ["Large"]) [P 5.5 -3.0]]
-      ] &
-   #hudOptions .~ mempty &
-   #svgOptions %~ ((#outerPad .~ Nothing) . (#chartAspect .~ UnadjustedAspect))
+  mempty
+    & #chartList
+    .~ vert
+      0.02
+      [ hori
+          0.02
+          [ [ Chart BlankA [R -0.4 0.4 -1 5],
+              Chart (TextA (defaultTextStyle & #size .~ 0.6 & #rotation .~ Just (pi / 2)) ["Sweep"]) [P 0.1 2]
+            ],
+            vert
+              0.02
+              [ [ Chart BlankA [R -0.25 0.25 -1 2],
+                  Chart (TextA (defaultTextStyle & #size .~ 0.4 & #rotation .~ Just (pi / 2)) ["True"]) [P 0.1 0.5]
+                ],
+                [ Chart BlankA [R -0.25 0.25 -1 2],
+                  Chart (TextA (defaultTextStyle & #size .~ 0.4 & #rotation .~ Just (pi / 2)) ["False"]) [P 0.1 0.5]
+                ]
+              ],
+            vert
+              0.02
+              [ checkFlags False True (setOpac 0.3 dark) & view #chartList,
+                checkFlags False False (setOpac 0.3 dark) & view #chartList,
+                [ Chart BlankA [R -1 2 -0.25 0.25],
+                  Chart (TextA (defaultTextStyle & #size .~ 0.4) ["False"]) [P 0.5 -0.1]
+                ]
+              ],
+            vert
+              0.02
+              [ checkFlags True True (setOpac 0.3 dark) & view #chartList,
+                checkFlags True False (setOpac 0.3 dark) & view #chartList,
+                [ Chart BlankA [R -1 2 -0.25 0.25],
+                  Chart (TextA (defaultTextStyle & #size .~ 0.4) ["True"]) [P 0.5 -0.1]
+                ]
+              ]
+          ],
+        [ Chart BlankA [R 0 9 -2.75 -3.25],
+          Chart (TextA (defaultTextStyle & #size .~ 0.6) ["Large"]) [P 5.5 -3.0]
+        ]
+      ]
+    & #hudOptions
+    .~ mempty
+    & #svgOptions %~ ((#outerPad .~ Nothing) . (#chartAspect .~ UnadjustedAspect))
 
 checkFlags :: Bool -> Bool -> Colour -> ChartSvg
 checkFlags large sweep co =
-  mempty &
-  #hudOptions .~ defaultHudOptions &
-  #svgOptions . #chartAspect .~ UnadjustedAspect &
-  #chartList .~ [c1, c2, ell, arc1]
+  mempty
+    & #hudOptions .~ defaultHudOptions
+    & #svgOptions . #chartAspect .~ UnadjustedAspect
+    & #chartList .~ [c1, c2, ell, arc1]
   where
     c = Point 1.0 1.0
     p1 = ArcPosition (Point 0.0 1.0) (Point 1.0 0.0) (ArcInfo (Point 1.0 1.0) 0 large sweep)
     ps1 = singletonPie' c p1
     (ArcCentroid c' r phi' ang0 angd) = arcCentroid p1
     arc1 = Chart (PathA (defaultPathStyle & #color .~ co & #borderColor .~ setOpac 0.5 dark) (fst <$> ps1)) (PointXY . snd <$> ps1)
-    c1 = Chart (LineA $ defaultLineStyle & #width .~ 0.02 & #color .~ setOpac 0.2 dark) (PointXY . ellipse (Point 1.0 1.0) (Point 1.0 1.0) 0 . (\x -> 0 + 2 * pi * x / 100.0) <$> [0..100])
-    c2 = Chart (LineA $ defaultLineStyle & #width .~ 0.02 & #color .~ setOpac 0.2 dark) (PointXY . ellipse (Point 0.0 0.0) (Point 1.0 1.0) 0 . (\x -> 0 + 2 * pi * x / 100.0) <$> [0..100])
-    ell = Chart (LineA $ defaultLineStyle & #width .~ 0.05 & #color .~ setOpac 0.5 co) (PointXY . ellipse c' r phi' . (\x -> ang0 + angd * x / 100.0) <$> [0..100])
+    c1 = Chart (LineA $ defaultLineStyle & #width .~ 0.02 & #color .~ setOpac 0.2 dark) (PointXY . ellipse (Point 1.0 1.0) (Point 1.0 1.0) 0 . (\x -> 0 + 2 * pi * x / 100.0) <$> [0 .. 100])
+    c2 = Chart (LineA $ defaultLineStyle & #width .~ 0.02 & #color .~ setOpac 0.2 dark) (PointXY . ellipse (Point 0.0 0.0) (Point 1.0 1.0) 0 . (\x -> 0 + 2 * pi * x / 100.0) <$> [0 .. 100])
+    ell = Chart (LineA $ defaultLineStyle & #width .~ 0.05 & #color .~ setOpac 0.5 co) (PointXY . ellipse c' r phi' . (\x -> ang0 + angd * x / 100.0) <$> [0 .. 100])
 
 -- | quad example
 --
 -- ![quad example](other/quad.svg)
 quadExample :: ChartSvg
 quadExample =
-  mempty &
-   #chartList .~ [path', curve, c0, bbox] &
-   #hudOptions .~ defaultHudOptions &
-   #svgOptions %~ ((#outerPad ?~ 0.05) . (#chartAspect .~ ChartAspect))
+  mempty
+    & #chartList .~ [path', curve, c0, bbox]
+    & #hudOptions .~ defaultHudOptions
+    & #svgOptions %~ ((#outerPad ?~ 0.05) . (#chartAspect .~ ChartAspect))
   where
     p@(QuadPosition start end control) = QuadPosition (Point 0 0) (Point 1 1) (Point 2 -1)
     ps = singletonQuad p
-    path' = Chart (PathA (defaultPathStyle & #color .~ setOpac 0.1 (palette1 List.!! 2) & #borderColor .~ transparent) (fst <$> ps)) (PointXY . snd <$> ps)
-    curve = Chart (LineA $ defaultLineStyle & #width .~ 0.002 & #color .~ (palette1 List.!! 1)) (PointXY . quadBezier p . (/100.0) <$> [0..100])
+    path' = Chart (PathA (defaultPathStyle & #color .~ setOpac 0.1 (palette1 2) & #borderColor .~ transparent) (fst <$> ps)) (PointXY . snd <$> ps)
+    curve = Chart (LineA $ defaultLineStyle & #width .~ 0.002 & #color .~ palette1 1) (PointXY . quadBezier p . (/ 100.0) <$> [0 .. 100])
     c0 = Chart (GlyphA defaultGlyphStyle) (PointXY <$> [start, end, control])
     bbox = Chart (RectA $ defaultRectStyle & #borderSize .~ 0.002 & #color .~ Colour 0.4 0.4 0.8 0.1 & #borderColor .~ Colour 0.5 0.5 0.5 1) [RectXY (quadBox p)]
 
@@ -535,41 +541,43 @@
 -- ![cubic example](other/cubic.svg)
 cubicExample :: ChartSvg
 cubicExample =
-  mempty &
-   #chartList .~ [path', curve, c0, bbox] &
-   #hudOptions .~ mempty &
-   #svgOptions %~ ((#outerPad ?~ 0.02) . (#chartAspect .~ ChartAspect))
+  mempty
+    & #chartList .~ [path', curve, c0, bbox]
+    & #hudOptions .~ mempty
+    & #svgOptions %~ ((#outerPad ?~ 0.02) . (#chartAspect .~ ChartAspect))
   where
     p@(CubicPosition start end control1 control2) = CubicPosition (Point 0 0) (Point 1 1) (Point 1 0) (Point 0 1)
     ps = singletonCubic p
-    path' = Chart (PathA (defaultPathStyle & #color .~ setOpac 0.1 (palette1 List.!! 2) & #borderColor .~ transparent) (fst <$> ps)) (PointXY . snd <$> ps)
-    curve = Chart (LineA $ defaultLineStyle & #width .~ 0.002 & #color .~ (palette1 List.!! 1)) (PointXY . cubicBezier p . (/100.0) <$> [0..100])
+    path' = Chart (PathA (defaultPathStyle & #color .~ setOpac 0.1 (palette1 2) & #borderColor .~ transparent) (fst <$> ps)) (PointXY . snd <$> ps)
+    curve = Chart (LineA $ defaultLineStyle & #width .~ 0.002 & #color .~ palette1 1) (PointXY . cubicBezier p . (/ 100.0) <$> [0 .. 100])
     c0 = Chart (GlyphA defaultGlyphStyle) (PointXY <$> [start, end, control1, control2, cubicBezier p 0.8])
     bbox = Chart (RectA $ defaultRectStyle & #borderSize .~ 0.002 & #color .~ Colour 0.4 0.4 0.8 0.1 & #borderColor .~ Colour 0.5 0.5 0.5 1) [RectXY (cubicBox p)]
 
 -- | The common way to create a surface chart is usually a grid over a function.
 --
 -- ![surface example](other/surface.svg)
---
 surfaceExample :: ChartSvg
 surfaceExample =
-  mempty &
-  #hudList .~ hs &
-  #chartList .~ cs &
-  #svgOptions .~ (defaultSvgOptions & #cssOptions .~ UseCssCrisp)
+  mempty
+    & #hudList .~ hs
+    & #chartList .~ cs
+    & #svgOptions .~ (defaultSvgOptions & #cssOptions .~ UseCssCrisp)
   where
     t = "rosenbrock"
     grain = Point 20 20
     r = one
     f = fst . bimap (-1.0 *) (-1.0 .*) . rosenbrock 1 10
     (cs, hs) =
-      surfacefl f
-      (defaultSurfaceOptions &
-       #soGrain .~ grain &
-       #soRange .~ r &
-       #soStyle . #surfaceColors .~ take 6 palette1)
-      (defaultSurfaceLegendOptions t &
-       #sloStyle . #surfaceColors .~ take 6 palette1)
+      surfacefl
+        f
+        ( defaultSurfaceOptions
+            & #soGrain .~ grain
+            & #soRange .~ r
+            & #soStyle . #surfaceColors .~ (palette1 <$> [0 .. 5])
+        )
+        ( defaultSurfaceLegendOptions t
+            & #sloStyle . #surfaceColors .~ (palette1 <$> [0 .. 5])
+        )
 
 -- | arrow example
 --
@@ -578,25 +586,25 @@
 -- ![arrow example](other/arrow.svg)
 arrowExample :: ChartSvg
 arrowExample =
-  mempty &
-  #hudOptions .~ (defaultHudOptions & #hudAxes %~ fmap (#axisTick . #ltick .~ Nothing)) &
-  #chartList .~ ((\p -> chart (tail . f $ p) (angle . f $ p) p) <$> ps) &
-  #svgOptions .~ defaultSvgOptions
+  mempty
+    & #hudOptions .~ (defaultHudOptions & #hudAxes %~ fmap (#axisTick . #ltick .~ Nothing))
+    & #chartList .~ ((\p -> chart (tail . f $ p) (angle . f $ p) p) <$> ps)
+    & #svgOptions .~ defaultSvgOptions
   where
     f = snd . bimap (-1.0 *) (-1.0 .*) . rosenbrock 1 10
     ps = grid MidPos (one :: Rect Double) (Point 10 10 :: Point Int) :: [Point Double]
     arrow = PathGlyph "M -1 0 L 1 0 M 1 0 L 0.4 0.3 M 1 0 L 0.4 -0.3"
     gs s r' =
-      defaultGlyphStyle &
-      #borderSize .~ 0.05 &
-      #size .~ s &
-      #borderColor .~ dark &
-      #rotation .~ Just r' &
-      #shape .~ arrow
+      defaultGlyphStyle
+        & #borderSize .~ 0.05
+        & #size .~ s
+        & #borderColor .~ dark
+        & #rotation .~ Just r'
+        & #shape .~ arrow
     chart s r' p = Chart (GlyphA (gs s r')) [PointXY p]
 
     tail :: Point Double -> Double
-    tail = max 0.05 . min 0.02 . (*0.01) . (/avmag) . norm
+    tail = max 0.05 . min 0.02 . (* 0.01) . (/ avmag) . norm
 
     avmag = sum (norm . f <$> ps) / fromIntegral (length ps)
 
@@ -608,7 +616,7 @@
 -- > f'y = 2 * b * y - 2 * b * x^2
 -- > f a b (Point x y) = (a^2 - 2ax + x^2 + b * y^2 - b * 2 * y * x^2 + b * x^4, Point (-2a + 2 * x - b * 4 * y * x + 4 * b * x ^ 3), 2 * b * y - 2 * b * x^2)
 rosenbrock :: Double -> Double -> Point Double -> (Double, Point Double)
-rosenbrock a b (Point x y) = (a^2 - 2*a*x + x^2 + b * y^2 - b * 2 * y * x^2 + b * x^4, Point (-2*a + 2 * x - b * 4 * y * x + 4 * b * x^3) (2 * b * y - 2 * b * x^2))
+rosenbrock a b (Point x y) = (a ^ 2 - 2 * a * x + x ^ 2 + b * y ^ 2 - b * 2 * y * x ^ 2 + b * x ^ 4, Point (-2 * a + 2 * x - b * 4 * y * x + 4 * b * x ^ 3) (2 * b * y - 2 * b * x ^ 2))
 
 -- | Run this to refresh haddock example SVGs.
 writeAllExamples :: IO ()
diff --git a/src/Chart/Reanimate.hs b/src/Chart/Reanimate.hs
--- a/src/Chart/Reanimate.hs
+++ b/src/Chart/Reanimate.hs
@@ -2,101 +2,74 @@
 {-# LANGUAGE OverloadedLabels #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RebindableSyntax #-}
-{-# LANGUAGE TupleSections #-}
-{-# LANGUAGE NoImplicitPrelude #-}
 {-# OPTIONS_GHC -fno-warn-name-shadowing #-}
 
 -- | Integration of reanimate and chart-svg
 module Chart.Reanimate
-  ( ReanimateConfig(..),
+  ( ReanimateConfig (..),
     defaultReanimateConfig,
-    reanimChartSvg,
     animChartSvg,
+    ChartReanimate (..),
     chartReanimate,
-    groupTreeA,
+    toTreeA,
     tree,
-    toPixelRGBA8,
-    daText,
-    fromFile,
-    translateDA,
-    scaleDA,
+    treeFromFile,
   )
 where
 
-import Chart as C hiding (transform, Line, renderChartsWith)
+import Chart as C hiding (Line, renderChartsWith, transform)
 import Codec.Picture.Types
 import Control.Lens hiding (transform)
 import qualified Data.Attoparsec.Text as A
+import Graphics.SvgTree as Svg hiding (Text)
+import qualified Graphics.SvgTree.PathParser as Svg
 import Linear.V2
 import NumHask.Prelude hiding (fold)
 import Reanimate as Re
-import qualified Graphics.SvgTree.PathParser as Svg
-import Graphics.SvgTree as Svg hiding (Text)
 
+-- | global reanimate configuration.
+--
+-- >>> defaultReanimateConfig
+-- ReanimateConfig {duration = 5.0, background = Just "black", globalFontFamily = Just ["Arial","Helvetica","sans-serif"], globalFontStyle = Just FontStyleNormal, globalAlignment = AlignxMinYMin}
 data ReanimateConfig = ReanimateConfig
   { duration :: Double,
     background :: Maybe Text,
     globalFontFamily :: Maybe [Text],
     globalFontStyle :: Maybe Svg.FontStyle,
     globalAlignment :: Svg.Alignment
-  } deriving (Eq, Show, Generic)
+  }
+  deriving (Eq, Show, Generic)
 
+-- |
 defaultReanimateConfig :: ReanimateConfig
 defaultReanimateConfig = ReanimateConfig 5 (Just "black") (Just ["Arial", "Helvetica", "sans-serif"]) (Just FontStyleNormal) AlignxMinYMin
 
-reanimChartSvg :: ReanimateConfig -> (Double -> ChartSvg) -> IO ()
-reanimChartSvg cfg cs =
-  reanimate $ animChartSvg cfg cs
-
+-- | Animate a ChartSvg animation.
 animChartSvg :: ReanimateConfig -> (Double -> ChartSvg) -> Animation
 animChartSvg cfg cs =
-  mkAnimation (view #duration cfg) $ groupTreeA cfg cs
+  mkAnimation (view #duration cfg) $ toTreeA cfg cs
 
 globalAtts :: ReanimateConfig -> Svg.DrawAttributes
 globalAtts cfg =
-  mempty &
-    maybe id (\x -> fontFamily .~ Last (Just (fmap unpack x)))
-     (view #globalFontFamily cfg) .
-    maybe id (\x -> fontStyle .~ Last (Just x))
-     (view #globalFontStyle cfg)
-
-data ChartReanimate = ChartReanimate { trees :: [Tree], box :: Rect Double, size :: C.Point Double} deriving (Eq, Show, Generic)
-
--- | create a Tree maker from a duration, and a chartsvg maker.
-groupTreeA :: ReanimateConfig -> (Double -> ChartSvg) -> Double -> Tree
-groupTreeA cfg cs x =
-  reCss (cs x & view (#svgOptions . #cssOptions)) $
-  mkGroup $ (mkBackground . unpack <$> maybeToList (view #background cfg)) <>
-  [ (\cr ->
-       let (Rect x z y w) =
-             view #box cr in
-         withViewBox' (x,y,z-x,w-y)
-         (PreserveAspectRatio False (view #globalAlignment cfg) Nothing) $
-         flipYAxis $
-         groupTrees (globalAtts cfg) $ view #trees cr) $
-    chartReanimate
-    (cs x)
-  ]
-
-reCss :: CssOptions -> (Tree -> Tree)
-reCss NoCssOptions = id
-reCss UseCssCrisp = Svg.cssApply (Svg.cssRulesOfText "* { shape-rendering: crispEdges; }")
-reCss UseGeometricPrecision = Svg.cssApply (Svg.cssRulesOfText "* { shape-rendering: geometricPrecision; }")
+  mempty
+    & maybe
+      id
+      (\x -> fontFamily .~ Last (Just (fmap unpack x)))
+      (view #globalFontFamily cfg)
+      . maybe
+        id
+        (\x -> fontStyle .~ Last (Just x))
+        (view #globalFontStyle cfg)
 
-withViewBox' :: (Double, Double, Double, Double) -> Svg.PreserveAspectRatio -> Tree -> Tree
-withViewBox' vbox par child = Re.translate (-screenWidth/2) (-screenHeight/2) $
-  svgTree Document
-  { _documentViewBox = Just vbox
-  , _documentWidth = Just (Num screenWidth)
-  , _documentHeight = Just (Num screenHeight)
-  , _documentElements = [child]
-  , _documentDescription = ""
-  , _documentLocation = ""
-  , _documentAspectRatio = par
+-- | The output of the raw translation of ChartSvg to a reanimate svg tree.
+data ChartReanimate = ChartReanimate
+  { trees :: [Tree],
+    box :: Rect Double,
+    size :: C.Point Double
   }
+  deriving (Eq, Show, Generic)
 
 -- | Render a 'ChartSvg' to 'Tree's, the fitted chart viewbox, and the suggested SVG dimensions
---
 chartReanimate :: ChartSvg -> ChartReanimate
 chartReanimate cs = ChartReanimate ts rect' size'
   where
@@ -105,6 +78,44 @@
     cl' = renderToCharts cs
     ts = tree <$> cl''
 
+-- | convert a ChartSvg animation to a Tree animation.
+toTreeA :: ReanimateConfig -> (Double -> ChartSvg) -> Double -> Tree
+toTreeA cfg cs x =
+  reCss (cs x & view (#svgOptions . #cssOptions)) $
+    mkGroup $
+      (mkBackground . unpack <$> maybeToList (view #background cfg))
+        <> [ ( \cr ->
+                 let (Rect x z y w) =
+                       view #box cr
+                  in withViewBox'
+                       (x, y, z - x, w - y)
+                       (PreserveAspectRatio False (view #globalAlignment cfg) Nothing)
+                       $ flipYAxis $
+                         groupTrees (globalAtts cfg) $ view #trees cr
+             )
+               $ chartReanimate
+                 (cs x)
+           ]
+
+reCss :: CssOptions -> (Tree -> Tree)
+reCss NoCssOptions = id
+reCss UseCssCrisp = Svg.cssApply (Svg.cssRulesOfText "* { shape-rendering: crispEdges; }")
+reCss UseGeometricPrecision = Svg.cssApply (Svg.cssRulesOfText "* { shape-rendering: geometricPrecision; }")
+
+withViewBox' :: (Double, Double, Double, Double) -> Svg.PreserveAspectRatio -> Tree -> Tree
+withViewBox' vbox par child =
+  Re.translate (- screenWidth / 2) (- screenHeight / 2) $
+    svgTree
+      Document
+        { _documentViewBox = Just vbox,
+          _documentWidth = Just (Num screenWidth),
+          _documentHeight = Just (Num screenHeight),
+          _documentElements = [child],
+          _documentDescription = "",
+          _documentLocation = "",
+          _documentAspectRatio = par
+        }
+
 -- | Rectange svg
 treeRect :: Rect Double -> Tree
 treeRect a =
@@ -159,10 +170,12 @@
       (pointSvg (C.Point (x + s / 2) y))
 treeShape (PathGlyph path) s p =
   Svg.PathTree
-  (Svg.Path
-   (Svg.defaultSvg &
-    (Svg.drawAttributes %~ scaleDA (C.Point s s) . translateDA p))
-    (either mempty id $ A.parseOnly Svg.pathParser path))
+    ( Svg.Path
+        ( Svg.defaultSvg
+            & (Svg.drawAttributes %~ scaleDA (C.Point s s) . translateDA p)
+        )
+        (either mempty id $ A.parseOnly Svg.pathParser path)
+    )
 
 -- | GlyphStyle to svg Tree
 treeGlyph :: GlyphStyle -> C.Point Double -> Tree
@@ -181,13 +194,15 @@
 treePath :: [PathInfo Double] -> [C.Point Double] -> Tree
 treePath s p =
   PathTree $
-  Path mempty (zipWith
-               (curry toPathCommand)
-               s
-               (fmap (\(C.Point x y) -> C.Point x (-y)) p))
+    Path
+      mempty
+      ( zipWith
+          (curry toPathCommand)
+          s
+          (fmap (\(C.Point x y) -> C.Point x (- y)) p)
+      )
 
 -- | convert a 'Chart' to a 'Tree'
---
 tree :: Chart Double -> Tree
 tree (Chart (TextA s ts) xs) =
   groupTrees (daText s) (zipWith (treeText s) ts (toPoint <$> xs))
@@ -208,24 +223,25 @@
   GroupTree (drawAttributes %~ (<> da') $ groupChildren .~ tree' $ defaultSvg)
 
 -- * DrawAttribute computations
+
 daRect :: RectStyle -> DrawAttributes
 daRect o =
-  mempty &
-  (strokeWidth .~ Last (Just $ Num (o ^. #borderSize))) &
-  (strokeColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #borderColor))) &
-  (strokeOpacity ?~ realToFrac (opac $ o ^. #borderColor)) &
-  (fillColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #color))) &
-  (fillOpacity ?~ realToFrac (opac $ o ^. #color))
+  mempty
+    & (strokeWidth .~ Last (Just $ Num (o ^. #borderSize)))
+    & (strokeColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #borderColor)))
+    & (strokeOpacity ?~ realToFrac (opac $ o ^. #borderColor))
+    & (fillColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #color)))
+    & (fillOpacity ?~ realToFrac (opac $ o ^. #color))
 
 daText :: () => TextStyle -> DrawAttributes
 daText o =
-  mempty &
-  (fontSize .~ Last (Just $ Num (o ^. #size))) &
-  (strokeWidth .~ Last (Just $ Num 0)) &
-  (strokeColor .~ Last (Just FillNone)) &
-  (fillColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #color))) &
-  (fillOpacity ?~ realToFrac (opac $ o ^. #color)) &
-  (textAnchor .~ Last (Just (toTextAnchor $ o ^. #anchor)))
+  mempty
+    & (fontSize .~ Last (Just $ Num (o ^. #size)))
+    & (strokeWidth .~ Last (Just $ Num 0))
+    & (strokeColor .~ Last (Just FillNone))
+    & (fillColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #color)))
+    & (fillOpacity ?~ realToFrac (opac $ o ^. #color))
+    & (textAnchor .~ Last (Just (toTextAnchor $ o ^. #anchor)))
   where
     toTextAnchor :: Anchor -> Svg.TextAnchor
     toTextAnchor AnchorMiddle = TextAnchorMiddle
@@ -234,30 +250,39 @@
 
 daGlyph :: GlyphStyle -> DrawAttributes
 daGlyph o =
-  mempty &
-  (strokeWidth .~ Last (Just $ Num (o ^. #borderSize))) &
-  (strokeColor .~
-   Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #borderColor))) &
-  (strokeOpacity ?~ realToFrac (opac $ o ^. #borderColor)) &
-  (fillColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #color))) &
-  (fillOpacity ?~ realToFrac (opac $ o ^. #color)) &
-  maybe id (\(C.Point x y) -> transform ?~ [Translate x (-y)]) (o ^. #translate)
+  mempty
+    & (strokeWidth .~ Last (Just $ Num (o ^. #borderSize)))
+    & ( strokeColor
+          .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #borderColor))
+      )
+    & (strokeOpacity ?~ realToFrac (opac $ o ^. #borderColor))
+    & (fillColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #color)))
+    & (fillOpacity ?~ realToFrac (opac $ o ^. #color))
+    & maybe id (\(C.Point x y) -> transform ?~ [Translate x (- y)]) (o ^. #translate)
 
 daLine :: LineStyle -> DrawAttributes
 daLine o =
-  mempty &
-  (strokeWidth .~ Last (Just $ Num (o ^. #width))) &
-  (strokeColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #color))) &
-  (strokeOpacity ?~ realToFrac (opac $ o ^. #color)) &
-  (fillColor .~ Last (Just FillNone)) &
-  maybe id (\x -> strokeLineCap .~ Last (Just $ fromLineCap' x))
-  (o ^. #linecap) &
-  maybe id (\x -> strokeLineJoin .~ Last (Just $ fromLineJoin' x))
-  (o ^. #linejoin) &
-  maybe id (\x -> strokeOffset .~ Last (Just $ Num x))
-  (o ^. #dashoffset) &
-  maybe id (\xs -> strokeDashArray .~ Last (Just (Num <$> xs)))
-  (o ^. #dasharray)
+  mempty
+    & (strokeWidth .~ Last (Just $ Num (o ^. #width)))
+    & (strokeColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #color)))
+    & (strokeOpacity ?~ realToFrac (opac $ o ^. #color))
+    & (fillColor .~ Last (Just FillNone))
+    & maybe
+      id
+      (\x -> strokeLineCap .~ Last (Just $ fromLineCap' x))
+      (o ^. #linecap)
+    & maybe
+      id
+      (\x -> strokeLineJoin .~ Last (Just $ fromLineJoin' x))
+      (o ^. #linejoin)
+    & maybe
+      id
+      (\x -> strokeOffset .~ Last (Just $ Num x))
+      (o ^. #dashoffset)
+    & maybe
+      id
+      (\xs -> strokeDashArray .~ Last (Just (Num <$> xs)))
+      (o ^. #dasharray)
 
 fromLineCap' :: LineCap -> Svg.Cap
 fromLineCap' LineCapButt = CapButt
@@ -271,13 +296,15 @@
 
 daPath :: PathStyle -> DrawAttributes
 daPath o =
-  mempty &
-  (strokeWidth .~ Last (Just $ Num (o ^. #borderSize))) &
-  (strokeColor .~ Last
-   (Just $ ColorRef (toPixelRGBA8 $ o ^. #borderColor))) &
-  (strokeOpacity ?~ realToFrac (opac $ o ^. #borderColor)) &
-  (fillColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #color))) &
-  (fillOpacity ?~ realToFrac (opac $ o ^. #color))
+  mempty
+    & (strokeWidth .~ Last (Just $ Num (o ^. #borderSize)))
+    & ( strokeColor
+          .~ Last
+            (Just $ ColorRef (toPixelRGBA8 $ o ^. #borderColor))
+      )
+    & (strokeOpacity ?~ realToFrac (opac $ o ^. #borderColor))
+    & (fillColor .~ Last (Just $ ColorRef (toPixelRGBA8 $ o ^. #color)))
+    & (fillOpacity ?~ realToFrac (opac $ o ^. #color))
 
 -- * svg primitives
 
@@ -299,7 +326,7 @@
 rotatePDA :: (HasDrawAttributes s) => Double -> C.Point Double -> s -> s
 rotatePDA a (C.Point x y) s = s & transform %~ (Just . maybe r (<> r))
   where
-    r = [Rotate (-a*180/pi) (Just (x, -y))]
+    r = [Rotate (- a * 180 / pi) (Just (x, - y))]
 
 -- | A DrawAttributes to translate by a Point.
 translateDA :: (HasDrawAttributes s) => C.Point Double -> s -> s
@@ -321,7 +348,7 @@
     . (rectHeight .~ Just (Num (w - y)))
 
 -- | import a Tree from a file
-fromFile :: FilePath -> IO Tree
-fromFile fp = do
+treeFromFile :: FilePath -> IO Tree
+treeFromFile fp = do
   t <- Svg.loadSvgFile fp
   pure $ maybe Svg.None Re.unbox t
diff --git a/src/Chart/Render.hs b/src/Chart/Render.hs
--- a/src/Chart/Render.hs
+++ b/src/Chart/Render.hs
@@ -38,26 +38,25 @@
 where
 
 import Chart.Types
-import Data.Colour
-import Data.Path
 import Control.Lens hiding (transform)
+import Data.Colour
 import Data.Generics.Labels ()
+import Data.Path
+import qualified Data.Text as Text
 import qualified Data.Text.Lazy as Lazy
 import Lucid
-import qualified Lucid.Base as Lucid
 import Lucid.Base
+import qualified Lucid.Base as Lucid
 import NumHask.Prelude
 import NumHask.Space as NH hiding (Element)
-import qualified Data.Text as Text
 
 -- | Specification of a chart for rendering to SVG
-data ChartSvg
-  = ChartSvg
-      { svgOptions :: SvgOptions,
-        hudOptions :: HudOptions,
-        hudList :: [Hud Double],
-        chartList :: [Chart Double]
-      }
+data ChartSvg = ChartSvg
+  { svgOptions :: SvgOptions,
+    hudOptions :: HudOptions,
+    hudList :: [Hud Double],
+    chartList :: [Chart Double]
+  }
   deriving (Generic)
 
 instance Semigroup ChartSvg where
@@ -68,6 +67,7 @@
   mempty = ChartSvg defaultSvgOptions mempty [] []
 
 -- * rendering
+
 -- | @svg@ element + svg 2 attributes
 svg2Tag :: Term [Attribute] (s -> t) => s -> t
 svg2Tag m =
@@ -81,8 +81,8 @@
 renderToSvg csso (Point w' h') (Rect x z y w) cs =
   with
     ( svg2Tag
-        ( cssText csso <>
-            mconcat (svg <$> cs)
+        ( cssText csso
+            <> mconcat (svg <$> cs)
         )
     )
     [ width_ (show w'),
@@ -105,20 +105,22 @@
 
 makeCharts :: ChartAspect -> HudOptions -> [Chart Double] -> [Chart Double]
 makeCharts asp ho cs =
-  let (hs', hc') = makeHud (padBox $ dataBoxes cs) ho in
-    runHud (initialCanvas asp (cs<>hc')) hs' (cs <> hc')
+  let (hs', hc') = makeHud (padBox $ dataBoxes cs) ho
+   in runHud (initialCanvas asp (cs <> hc')) hs' (cs <> hc')
 
 renderToCRS :: SvgOptions -> [Chart Double] -> ([Chart Double], Rect Double, Point Double)
 renderToCRS so cs = (cs', rect', size')
   where
     rect' = styleBoxesS cs' & maybe id padRect (so ^. #outerPad)
     cs' =
-      cs &
-      runHud penult [chartAspectHud (so ^. #chartAspect)] &
-      maybe id (\x -> frameChart x (fromMaybe 0 (so ^. #innerPad)))
-        (so ^. #chartFrame)
+      cs
+        & runHud penult [chartAspectHud (so ^. #chartAspect)]
+        & maybe
+          id
+          (\x -> frameChart x (fromMaybe 0 (so ^. #innerPad)))
+          (so ^. #chartFrame)
     Point w h = NH.width rect'
-    size' = Point ((so ^. #svgHeight)/h*w) (so ^. #svgHeight)
+    size' = Point ((so ^. #svgHeight) / h * w) (so ^. #svgHeight)
     penult = case so ^. #chartAspect of
       FixedAspect _ -> styleBoxesS cs
       CanvasAspect _ -> dataBoxesS cs
@@ -136,14 +138,16 @@
   where
     rect' = styleBoxesS cs' & maybe id padRect (so ^. #outerPad)
     cs' =
-      cs &
-      runHud penult [chartAspectHud (so ^. #chartAspect)] &
-      maybe id (\x -> frameChart x (fromMaybe 0 (so ^. #innerPad)))
-        (so ^. #chartFrame)
+      cs
+        & runHud penult [chartAspectHud (so ^. #chartAspect)]
+        & maybe
+          id
+          (\x -> frameChart x (fromMaybe 0 (so ^. #innerPad)))
+          (so ^. #chartFrame)
     cs'' =
       maybe [] (\c -> [Chart (RectA (blob c)) [RectXY rect']]) (so ^. #background) <> cs'
     Point w h = NH.width rect'
-    size' = Point ((so ^. #svgHeight)/h*w) (so ^. #svgHeight)
+    size' = Point ((so ^. #svgHeight) / h * w) (so ^. #svgHeight)
     penult = case so ^. #chartAspect of
       FixedAspect _ -> styleBoxesS cs
       CanvasAspect _ -> dataBoxesS cs
@@ -362,11 +366,11 @@
     term "stroke" (toHex $ o ^. #color),
     term "stroke-opacity" (show $ opac $ o ^. #color),
     term "fill" "none"
-  ] <>
-  maybe [] (\x -> [term "stroke-linecap" (fromLineCap x)]) (o ^. #linecap) <>
-  maybe [] (\x -> [term "stroke-linejoin" (fromLineJoin x)]) (o ^. #linejoin) <>
-  maybe [] (\x -> [term "stroke-dasharray" (fromDashArray x)]) (o ^. #dasharray) <>
-  maybe [] (\x -> [term "stroke-dashoffset" (show x)]) (o ^. #dashoffset)
+  ]
+    <> maybe [] (\x -> [term "stroke-linecap" (fromLineCap x)]) (o ^. #linecap)
+    <> maybe [] (\x -> [term "stroke-linejoin" (fromLineJoin x)]) (o ^. #linejoin)
+    <> maybe [] (\x -> [term "stroke-dasharray" (fromDashArray x)]) (o ^. #dasharray)
+    <> maybe [] (\x -> [term "stroke-dashoffset" (show x)]) (o ^. #dashoffset)
 
 -- | PathStyle to Attributes
 attsPath :: PathStyle -> [Lucid.Attribute]
@@ -390,10 +394,9 @@
 -- - from counter-clockwise is a positive rotation to clockwise is positive
 --
 -- - flip y dimension
---
 toRotateText :: Double -> Point Double -> Text
 toRotateText r (Point x y) =
-  "rotate(" <> show (-r*180/pi) <> ", " <> show x <> ", " <> show (- y) <> ")"
+  "rotate(" <> show (- r * 180 / pi) <> ", " <> show x <> ", " <> show (- y) <> ")"
 
 toScaleText :: Double -> Text
 toScaleText x =
diff --git a/src/Chart/Surface.hs b/src/Chart/Surface.hs
--- a/src/Chart/Surface.hs
+++ b/src/Chart/Surface.hs
@@ -33,16 +33,14 @@
 import NumHask.Space
 
 -- | Options for a Surface chart.
---
-data SurfaceOptions
-  = SurfaceOptions
-      { -- | surface style
-        soStyle :: SurfaceStyle,
-        -- | The grain or granularity of the chart
-        soGrain :: Point Int,
-        -- | Chart range
-        soRange :: Rect Double
-      }
+data SurfaceOptions = SurfaceOptions
+  { -- | surface style
+    soStyle :: SurfaceStyle,
+    -- | The grain or granularity of the chart
+    soGrain :: Point Int,
+    -- | Chart range
+    soRange :: Rect Double
+  }
   deriving (Show, Eq, Generic)
 
 -- | official style
@@ -56,27 +54,25 @@
 -- SurfaceStyle {surfaceColors = [Colour 0.69 0.35 0.16 1.00,Colour 0.65 0.81 0.89 1.00], surfaceRectStyle = RectStyle {borderSize = 0.0, borderColor = Colour 0.00 0.00 0.00 0.00, color = Colour 0.05 0.05 0.05 1.00}}
 --
 -- ![surface example](other/surface.svg)
-data SurfaceStyle
-  = SurfaceStyle
-      { -- | list of colours to interpolate between.
-        surfaceColors :: [Colour],
-        surfaceRectStyle :: RectStyle
-      }
+data SurfaceStyle = SurfaceStyle
+  { -- | list of colours to interpolate between.
+    surfaceColors :: [Colour],
+    surfaceRectStyle :: RectStyle
+  }
   deriving (Show, Eq, Generic)
 
 -- | The official surface style.
 defaultSurfaceStyle :: SurfaceStyle
 defaultSurfaceStyle =
-  SurfaceStyle (take 2 palette1) (blob dark)
+  SurfaceStyle (take 2 palette1_) (blob dark)
 
 -- | Main surface data elements
-data SurfaceData
-  = SurfaceData
-      { -- | XY Coordinates of surface.
-        surfaceRect :: Rect Double,
-        -- | Surface colour.
-        surfaceColor :: Colour
-      }
+data SurfaceData = SurfaceData
+  { -- | XY Coordinates of surface.
+    surfaceRect :: Rect Double,
+    -- | Surface colour.
+    surfaceColor :: Colour
+  }
   deriving (Show, Eq, Generic)
 
 -- | surface chart without any hud trimmings
@@ -120,18 +116,16 @@
     (cs, dr) = surfacef f po
 
 -- | Legend specialization for a surface chart.
---
-data SurfaceLegendOptions
-  = SurfaceLegendOptions
-      { sloStyle :: SurfaceStyle,
-        sloTitle :: Text,
-        -- | Width of the legend glyph
-        sloWidth :: Double,
-        -- | Resolution of the legend glyph
-        sloResolution :: Int,
-        sloAxisOptions :: AxisOptions,
-        sloLegendOptions :: LegendOptions
-      }
+data SurfaceLegendOptions = SurfaceLegendOptions
+  { sloStyle :: SurfaceStyle,
+    sloTitle :: Text,
+    -- | Width of the legend glyph
+    sloWidth :: Double,
+    -- | Resolution of the legend glyph
+    sloResolution :: Int,
+    sloAxisOptions :: AxisOptions,
+    sloLegendOptions :: LegendOptions
+  }
   deriving (Eq, Show, Generic)
 
 surfaceAxisOptions :: AxisOptions
@@ -166,7 +160,6 @@
     & #legendFrame .~ Nothing
 
 -- | Creation of the classical heatmap glyph within a legend context.
---
 surfaceLegendChart :: Range Double -> SurfaceLegendOptions -> [Chart Double]
 surfaceLegendChart dataRange l =
   padChart (l ^. #sloLegendOptions . #outerPad)
@@ -176,26 +169,35 @@
     a = makeSurfaceTick l pchart
     pchart
       | l ^. #sloLegendOptions . #lplace == PlaceBottom
-          || l ^. #sloLegendOptions . #lplace == PlaceTop = vertGlyph
+          || l ^. #sloLegendOptions . #lplace == PlaceTop =
+        vertGlyph
       | otherwise = horiGlyph
     t = Chart (TextA (l ^. #sloLegendOptions . #ltext & #anchor .~ AnchorStart) [l ^. #sloTitle]) [zero]
     hs = vert (l ^. #sloLegendOptions . #vgap) [a, [t]]
     vertGlyph :: [Chart Double]
     vertGlyph =
       zipWith
-      (\r c -> Chart (RectA $ blob c) [RectXY r])
-      ((\xr -> Ranges xr (Range 0 (l ^. #sloWidth))) <$> gridSpace dataRange
-       (l ^. #sloResolution))
-      ((\x -> blends x (l ^. #sloStyle . #surfaceColors)) <$>
-       grid MidPos (Range 0 1) (l ^. #sloResolution))
+        (\r c -> Chart (RectA $ blob c) [RectXY r])
+        ( (\xr -> Ranges xr (Range 0 (l ^. #sloWidth)))
+            <$> gridSpace
+              dataRange
+              (l ^. #sloResolution)
+        )
+        ( (\x -> blends x (l ^. #sloStyle . #surfaceColors))
+            <$> grid MidPos (Range 0 1) (l ^. #sloResolution)
+        )
     horiGlyph :: [Chart Double]
     horiGlyph =
       zipWith
-      (\r c -> Chart (RectA $ blob c) [RectXY r])
-      ((\yr -> Ranges (Range 0 (l ^. #sloWidth)) yr) <$> gridSpace dataRange
-       (l ^. #sloResolution))
-      ((\x -> blends x (l ^. #sloStyle . #surfaceColors)) <$>
-       grid MidPos (Range 0 1) (l ^. #sloResolution))
+        (\r c -> Chart (RectA $ blob c) [RectXY r])
+        ( (\yr -> Ranges (Range 0 (l ^. #sloWidth)) yr)
+            <$> gridSpace
+              dataRange
+              (l ^. #sloResolution)
+        )
+        ( (\x -> blends x (l ^. #sloStyle . #surfaceColors))
+            <$> grid MidPos (Range 0 1) (l ^. #sloResolution)
+        )
 
 isHori :: SurfaceLegendOptions -> Bool
 isHori l =
@@ -216,4 +218,3 @@
                ]
         )
     phud = runHudWith r' r hs pchart
-
diff --git a/src/Chart/Types.hs b/src/Chart/Types.hs
--- a/src/Chart/Types.hs
+++ b/src/Chart/Types.hs
@@ -111,8 +111,6 @@
     LegendOptions (..),
     defaultLegendOptions,
     legendHud,
-    legendChart,
-    legendEntry,
     Orientation (..),
     fromOrientation,
     toOrientation,
@@ -148,7 +146,6 @@
 import Data.Colour
 import Data.FormatN
 import Data.Generics.Labels ()
-import qualified Data.List as List
 import Data.Path
 import qualified Data.Text as Text
 import Data.Time
@@ -221,7 +218,7 @@
 scaleOpacAnn _ BlankA = BlankA
 
 scaleOpac :: Double -> Colour -> Colour
-scaleOpac x (Colour r g b o') = Colour r g b (o'*x)
+scaleOpac x (Colour r g b o') = Colour r g b (o' * x)
 
 -- | select a main colour
 colourAnn :: Colour -> Annotation -> Annotation
@@ -257,7 +254,7 @@
 
 -- | the style
 defaultRectStyle :: RectStyle
-defaultRectStyle = RectStyle 0.01 (palette1 List.!! 1) (palette1 List.!! 2)
+defaultRectStyle = RectStyle 0.01 (palette1 1) (palette1 2)
 
 -- | solid rectangle, no border
 --
@@ -346,8 +343,8 @@
 defaultGlyphStyle =
   GlyphStyle
     0.03
-    (palette1 List.!! 1)
-    (palette1 List.!! 2)
+    (palette1 1)
+    (palette1 2)
     0.003
     SquareGlyph
     Nothing
@@ -452,7 +449,7 @@
 -- | the style
 defaultPathStyle :: PathStyle
 defaultPathStyle =
-  PathStyle 0.01 (palette1 List.!! 1) (palette1 List.!! 2)
+  PathStyle 0.01 (palette1 1) (palette1 2)
 
 -- | Convert from a path command list to a PathA chart
 toPathChart :: PathStyle -> [(PathInfo Double, Point Double)] -> Chart Double
@@ -656,32 +653,33 @@
 -- | alter the colour
 colourHudOptions :: Colour -> HudOptions -> HudOptions
 colourHudOptions c ho =
-  ho &
-  #hudCanvas %~ fmap (#color %~ mix c) &
-  #hudTitles %~ fmap (#style . #color %~ mix c) &
-  #hudAxes %~ fmap (#axisBar %~ fmap (#rstyle . #color %~ mix c)) &
-  #hudAxes %~ fmap (#axisTick . #gtick %~ fmap (first ((#color %~ mix c) . (#borderColor %~ mix c)))) &
-  #hudAxes %~ fmap (#axisTick . #ttick %~ fmap (first (#color %~ mix c))) &
-  #hudAxes %~ fmap (#axisTick . #ltick %~ fmap (first (#color %~ mix c))) &
-  #hudLegend %~ fmap (first (#ltext %~ (#color %~ mix c))) &
-  #hudLegend %~ fmap (first (#legendFrame %~ fmap ((#color %~ mix c) . (#borderColor %~ mix c))))
+  ho
+    & #hudCanvas %~ fmap (#color %~ mix c)
+    & #hudTitles %~ fmap (#style . #color %~ mix c)
+    & #hudAxes %~ fmap (#axisBar %~ fmap (#rstyle . #color %~ mix c))
+    & #hudAxes %~ fmap (#axisTick . #gtick %~ fmap (first ((#color %~ mix c) . (#borderColor %~ mix c))))
+    & #hudAxes %~ fmap (#axisTick . #ttick %~ fmap (first (#color %~ mix c)))
+    & #hudAxes %~ fmap (#axisTick . #ltick %~ fmap (first (#color %~ mix c)))
+    & #hudLegend %~ fmap (first (#ltext %~ (#color %~ mix c)))
+    & #hudLegend %~ fmap (first (#legendFrame %~ fmap ((#color %~ mix c) . (#borderColor %~ mix c))))
 
+-- | adjust the opacity of HudOptions up or down geometrically (scaling by (*o))
 scaleOpacHudOptions :: HudOptions -> Double -> HudOptions
 scaleOpacHudOptions ho o =
-  ho &
-  #hudCanvas %~ fmap (#color %~ scaleOpac o) &
-  #hudTitles %~ fmap (#style . #color %~ scaleOpac o) &
-  #hudAxes %~ fmap (#axisBar %~ fmap (#rstyle . #color %~ scaleOpac o)) &
-  #hudAxes %~ fmap (#axisTick . #gtick %~ fmap (first ((#color %~ scaleOpac o) . (#borderColor %~ scaleOpac o)))) &
-  #hudAxes %~ fmap (#axisTick . #ttick %~ fmap (first (#color %~ scaleOpac o))) &
-  #hudAxes %~ fmap (#axisTick . #ltick %~ fmap (first (#color %~ scaleOpac o))) &
-  #hudLegend %~ fmap (first (#ltext %~ (#color %~ scaleOpac o))) &
-  #hudLegend %~ fmap (first (#legendFrame %~ fmap ((#color %~ scaleOpac o) . (#borderColor %~ scaleOpac o)))) &
-  #hudLegend %~ fmap (second (fmap (first (scaleOpacAnn o))))
+  ho
+    & #hudCanvas %~ fmap (#color %~ scaleOpac o)
+    & #hudTitles %~ fmap (#style . #color %~ scaleOpac o)
+    & #hudAxes %~ fmap (#axisBar %~ fmap (#rstyle . #color %~ scaleOpac o))
+    & #hudAxes %~ fmap (#axisTick . #gtick %~ fmap (first ((#color %~ scaleOpac o) . (#borderColor %~ scaleOpac o))))
+    & #hudAxes %~ fmap (#axisTick . #ttick %~ fmap (first (#color %~ scaleOpac o)))
+    & #hudAxes %~ fmap (#axisTick . #ltick %~ fmap (first (#color %~ scaleOpac o)))
+    & #hudLegend %~ fmap (first (#ltext %~ (#color %~ scaleOpac o)))
+    & #hudLegend %~ fmap (first (#legendFrame %~ fmap ((#color %~ scaleOpac o) . (#borderColor %~ scaleOpac o))))
+    & #hudLegend %~ fmap (second (fmap (first (scaleOpacAnn o))))
 
 -- | colour reset but scaling opacity
 mix :: Colour -> Colour -> Colour
-mix (Colour r g b o') (Colour _ _ _ o) = Colour r g b (o'*o)
+mix (Colour r g b o') (Colour _ _ _ o) = Colour r g b (o' * o)
 
 -- | The official hud canvas
 defaultCanvas :: RectStyle
@@ -752,8 +750,8 @@
 defaultTitle txt =
   Title
     txt
-    ( defaultTextStyle &
-      #size .~ 0.12
+    ( defaultTextStyle
+        & #size .~ 0.12
     )
     PlaceTop
     AnchorMiddle
@@ -866,7 +864,7 @@
   }
   deriving (Show, Eq, Generic)
 
--- | The official legend options 
+-- | The official legend options
 defaultLegendOptions :: LegendOptions
 defaultLegendOptions =
   LegendOptions
@@ -1642,21 +1640,21 @@
 
 -- | useful for testing bounding boxes
 frameAllCharts :: [Chart Double] -> [Chart Double]
-frameAllCharts cs = mconcat $ frameChart (border 0.004 light) 0.004 . (:[]) <$> cs
+frameAllCharts cs = mconcat $ frameChart (border 0.004 light) 0.004 . (: []) <$> cs
 
 -- | horizontally stack a list of list of charts (proceeding to the right) with a gap between
 hori :: Double -> [[Chart Double]] -> [Chart Double]
 hori _ [] = []
-hori gap cs = foldl step [] cs
+hori gap cs = foldl' step [] cs
   where
     step x a = x <> (a & fmap (#xys %~ fmap (\s -> P (widthx x) (aligny x - aligny a) + s)))
     widthx xs = maybe 0 (\(Rect x' z' _ _) -> z' - x' + gap) (styleBoxes xs)
-    aligny xs = maybe 0 (\(Rect _ _ y' w') -> (y'+w')/2) (styleBoxes xs)
+    aligny xs = maybe 0 (\(Rect _ _ y' w') -> (y' + w') / 2) (styleBoxes xs)
 
 -- | vertically stack a list of charts (proceeding upwards), aligning them to the left
 vert :: Double -> [[Chart Double]] -> [Chart Double]
 vert _ [] = []
-vert gap cs = foldl step [] cs
+vert gap cs = foldl' step [] cs
   where
     step x a = x <> (a & fmap (#xys %~ fmap (\s -> P (alignx x - alignx a) (widthy x) + s)))
     widthy xs = maybe 0 (\(Rect _ _ y' w') -> w' - y' + gap) (styleBoxes xs)
diff --git a/src/Chart/Various.hs b/src/Chart/Various.hs
--- a/src/Chart/Various.hs
+++ b/src/Chart/Various.hs
@@ -1,6 +1,5 @@
 {-# LANGUAGE OverloadedLabels #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE TupleSections #-}
 {-# LANGUAGE NoImplicitPrelude #-}
 {-# OPTIONS_GHC -fno-warn-name-shadowing #-}
 
@@ -36,7 +35,6 @@
 import Chart
 import Control.Lens
 import qualified Data.HashMap.Strict as HashMap
-import Data.List ((!!))
 import Data.Time (UTCTime (..))
 import NumHask.Prelude hiding (fold)
 import NumHask.Space
@@ -89,7 +87,7 @@
 
 -- | Can of the main palette
 stdLines :: Double -> [LineStyle]
-stdLines w = (\c -> defaultLineStyle & #color .~ c & #width .~ w) <$> palette1
+stdLines w = (\c -> defaultLineStyle & #color .~ c & #width .~ w) <$> palette1_
 
 -- | Legend template for a line chart.
 lineLegend :: Double -> [Text] -> [Colour] -> (LegendOptions, [(Annotation, Text)])
@@ -97,7 +95,7 @@
   ( defaultLegendOptions
       & #ltext . #size .~ 0.3
       & #lplace .~ PlaceBottom
-      & #legendFrame .~ Just (RectStyle 0.02 (palette1 !! 5) (palette1 !! 4)),
+      & #legendFrame .~ Just (RectStyle 0.02 (palette1 5) (palette1 4)),
     zipWith
       (\a r -> (LineA a, r))
       ((\c -> defaultLineStyle & #color .~ c & #width .~ w) <$> cs)
@@ -129,7 +127,7 @@
 
 -- | GlyphStyle palette
 gpaletteStyle :: Double -> [GlyphStyle]
-gpaletteStyle s = zipWith (\c g -> defaultGlyphStyle & #size .~ s & #color .~ c & #shape .~ fst g & #borderSize .~ snd g) palette1 gpalette
+gpaletteStyle s = zipWith (\c g -> defaultGlyphStyle & #size .~ s & #color .~ c & #shape .~ fst g & #borderSize .~ snd g) palette1_ gpalette
 
 -- | Glyph palette
 gpalette :: [(GlyphShape, Double)]
@@ -154,9 +152,9 @@
   [LineStyle] ->
   [AxisOptions] ->
   [[Double]] ->
-  (HudOptions, [Chart Double])
+  ChartSvg
 quantileChart title names ls as xs =
-  (hudOptions, chart')
+  mempty & #hudOptions .~ hudOptions & #chartList .~ chart'
   where
     hudOptions =
       defaultHudOptions
@@ -194,9 +192,9 @@
   Text ->
   [UTCTime] ->
   [Double] ->
-  (HudOptions, [Chart Double])
+  ChartSvg
 digitChart title utcs xs =
-  (hudOptions, [c])
+  mempty & #hudOptions .~ hudOptions & #chartList .~ [c]
   where
     hudOptions =
       defaultHudOptions
@@ -226,10 +224,10 @@
   Range Double ->
   Int ->
   [Double] ->
-  (HudOptions, [Chart Double])
+  ChartSvg
 histChart title names r g xs =
   barChart defaultBarOptions barData
-    & first (#hudTitles .~ [defaultTitle title])
+    & (#hudOptions . #hudTitles .~ [defaultTitle title])
   where
     barData = BarData [hr] names Nothing
     hcuts = grid OuterPos r g
@@ -246,8 +244,9 @@
   [Double] ->
   -- | quantile values
   [Double] ->
-  (HudOptions, [Chart Double])
-quantileHistChart title names qs vs = (hudOptions, [chart'])
+  ChartSvg
+quantileHistChart title names qs vs =
+  mempty & #hudOptions .~ hudOptions & #chartList .~ [chart']
   where
     hudOptions =
       defaultHudOptions
@@ -321,4 +320,3 @@
 -- | Chart for double list of Text.
 tableChart :: [[Text]] -> [Chart Double]
 tableChart tss = zipWith (\ts x -> Chart (TextA defaultTextStyle ts) (P x <$> take (length ts) [0 ..])) tss [0 ..]
-
diff --git a/src/Data/Colour.hs b/src/Data/Colour.hs
--- a/src/Data/Colour.hs
+++ b/src/Data/Colour.hs
@@ -28,28 +28,29 @@
     fromHex,
     unsafeFromHex,
     palette1,
+    palette1_,
     transparent,
     black,
     white,
     light,
     dark,
-    grey,
   )
 where
 
 import qualified Data.Attoparsec.Text as A
 import Data.FormatN
 import Data.Generics.Labels ()
+import qualified Data.List as List
 import qualified Data.Text as Text
 import Graphics.Color.Model
 import NumHask.Prelude as NHP
 import qualified Prelude as P
 
 -- | Wrapper for 'Color'.
-newtype Colour =
-  Colour'
+newtype Colour = Colour'
   { color' :: Color (Alpha RGB) Double
-  } deriving (Eq, Generic)
+  }
+  deriving (Eq, Generic)
 
 -- | Constructor pattern.
 pattern Colour :: Double -> Double -> Double -> Double -> Colour
@@ -99,11 +100,11 @@
 -- True
 --
 -- >>> blends 0.6 [black, (Colour 0.2 0.6 0.8 0.5), white]
--- RGBA 0.16 0.48 0.64 0.60
+-- Colour 0.36 0.68 0.84 0.60
 blends :: Double -> [Colour] -> Colour
 blends _ [] = light
 blends _ [c] = c
-blends x cs = blend r (cs P.!! i) (cs P.!! (i+1))
+blends x cs = blend r (cs P.!! i) (cs P.!! (i + 1))
   where
     l = length cs - 1
     x' = x * fromIntegral l
@@ -159,9 +160,16 @@
 i2d :: Int -> Char
 i2d i = chr (ord '0' + i)
 
--- | some RGBA colors
-palette1 :: [Colour]
-palette1 =
+-- | select a Colour from the palette
+--
+-- >>> palette1 0
+-- Colour 0.69 0.35 0.16 1.00
+palette1 :: Int -> Colour
+palette1 x = cycle palette1_ List.!! x
+
+-- | finite list of Colours
+palette1_ :: [Colour]
+palette1_ =
   [ Colour 0.69 0.35 0.16 1.00,
     Colour 0.65 0.81 0.89 1.00,
     Colour 0.12 0.47 0.71 1.00,
@@ -178,26 +186,42 @@
   ]
 
 -- |
+--
+-- >>> black
+-- Colour 0.00 0.00 0.00 1.00
 black :: Colour
 black = Colour 0 0 0 1
 
 -- |
+--
+-- >>> white
+-- Colour 0.99 0.99 0.99 1.00
 white :: Colour
 white = Colour 0.99 0.99 0.99 1
 
 -- |
+--
+-- For lighter huds against a dark background ...
+--
+-- > colourHudOptions light defaultHudOptions
+--
+-- >>> light
+-- Colour 0.94 0.94 0.94 1.00
 light :: Colour
 light = Colour 0.94 0.94 0.94 1
 
 -- |
+--
+-- dark is hardcoded in most of the default options.
+--
+-- >>> dark
+-- Colour 0.05 0.05 0.05 1.00
 dark :: Colour
 dark = Colour 0.05 0.05 0.05 1
 
-grey :: Colour
-grey = Colour 0.5 0.5 0.5 1
-
--- |
+-- | zero opacity black
+--
+-- >>> transparent
+-- Colour 0.00 0.00 0.00 0.00
 transparent :: Colour
 transparent = Colour 0 0 0 0
-
-
diff --git a/src/Data/FormatN.hs b/src/Data/FormatN.hs
--- a/src/Data/FormatN.hs
+++ b/src/Data/FormatN.hs
@@ -9,6 +9,7 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE RebindableSyntax #-}
+{-# LANGUAGE StrictData #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# OPTIONS_GHC -Wall #-}
 {-# OPTIONS_GHC -fno-warn-name-shadowing #-}
@@ -34,8 +35,8 @@
   )
 where
 
+import Data.Containers.ListUtils (nubOrd)
 import Data.Generics.Labels ()
-import Data.List (nub)
 import Data.Scientific
 import qualified Data.Text as Text
 import NumHask.Prelude
@@ -118,7 +119,7 @@
     (ds0, ds1) = splitAt (n + 1) ds
     r =
       (fromIntegral $ foldl' (\x a -> x * 10 + a) 0 ds0 :: Double)
-        + fromIntegral (foldl' (\x a -> x * 10 + a) 0 ds1) / (10.0^length ds1)
+        + fromIntegral (foldl' (\x a -> x * 10 + a) 0 ds1) / (10.0 ^ length ds1)
     r' = round r :: Integer
 
 -- | format numbers between 0.001 and 1,000,000 using digit and comma notation and exponential outside this range, with x significant figures.
@@ -214,7 +215,7 @@
   where
     precLoop f' n xs' =
       let s = f' (Just n) <$> xs'
-       in if s == nub s || n > 4
+       in if s == nubOrd s || n > 4
             then s
             else precLoop f' (n + 1) xs'
 
@@ -235,4 +236,3 @@
   where
     f' = formatN f x
     s' = show x
-    
diff --git a/src/Data/Path.hs b/src/Data/Path.hs
--- a/src/Data/Path.hs
+++ b/src/Data/Path.hs
@@ -1,12 +1,12 @@
-{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE AllowAmbiguousTypes #-}
 {-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE NegativeLiterals #-}
-{-# LANGUAGE RebindableSyntax #-}
 {-# LANGUAGE OverloadedLabels #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE AllowAmbiguousTypes #-}
-{-# OPTIONS_GHC -fno-warn-type-defaults #-}
+{-# LANGUAGE RebindableSyntax #-}
 {-# OPTIONS_GHC -fno-warn-name-shadowing #-}
+{-# OPTIONS_GHC -fno-warn-type-defaults #-}
 
 -- | SVG path manipulation
 module Data.Path
@@ -48,21 +48,22 @@
     toSingletonArc,
     pathBoxes,
     pathBox,
-  ) where
+  )
+where
 
-import qualified Graphics.SvgTree as SvgTree
-import Graphics.SvgTree (PathCommand (..), Origin(..))
-import Graphics.SvgTree.PathParser
-import qualified Data.Attoparsec.Text as A
-import qualified Data.Text as Text
-import NumHask.Space
-import NumHask.Prelude hiding (rotate)
-import qualified Linear
 import qualified Control.Foldl as L
 import Control.Lens hiding ((...))
+import qualified Data.Attoparsec.Text as A
+import Data.FormatN
 import Data.Generics.Labels ()
+import qualified Data.Text as Text
 import qualified Geom2D.CubicBezier as B
-import Data.FormatN
+import Graphics.SvgTree (Origin (..), PathCommand (..))
+import qualified Graphics.SvgTree as SvgTree
+import Graphics.SvgTree.PathParser
+import qualified Linear
+import NumHask.Prelude hiding (rotate)
+import NumHask.Space
 
 -- $setup
 -- >>> :set -XRebindableSyntax
@@ -78,7 +79,6 @@
 -- [SVG d](https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/d)
 --
 -- [SVG path](https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorial/Paths)
---
 
 -- | parse a raw path string
 --
@@ -87,23 +87,22 @@
 -- [MoveTo OriginAbsolute [V2 (-1.0) 0.5],EllipticalArc OriginAbsolute [(0.5,0.5,0.0,True,True,V2 0.0 (-1.2320508075688774)),(1.0,1.0,0.0,False,False,V2 (-0.5) (-0.3660254037844387)),(1.0,1.0,0.0,False,False,V2 (-1.0) 0.5)],EndPath]
 --
 -- https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/d
---
 parsePath :: Text -> [PathCommand]
 parsePath t = either (const []) id $ A.parseOnly pathParser t
 
--- | To fit in with the requirements of the 'Chart' interface, path instructions need to be decontructed into:
+-- | To fit in with the requirements of the library design, specifically the separation of what a chart is into XY data Points from representation of these points, path instructions need to be decontructed into:
 --
 -- - define a single chart element as a line.
 --
 -- - split a single path element into the start and end points of the line, which become the 'Chart.Types.xys' of a 'Chart.Types.Chart', and the rest of the information, which is called 'PathInfo' and incorporated into the 'Chart.Types.Chart' 'Chart.Types.annotation'.
 --
--- A lot of detail rides on whether the PathInfo is invariant to affine transformations of the 'Chart.Types.xys' points. Cubic and quadratic bezier paths need to be re-projected whenever 'Chart.Types.xys' are re-projected. Arcs are problematic (See 'Chart.Examples.problematic2' & 'Chart.Examples.problematic2').
-data PathInfo a =
-  StartI |
-  LineI |
-  CubicI (Point a) (Point a) |
-  QuadI (Point a) |
-  ArcI (ArcInfo a)
+-- An arc path is variant to affine transformations of the 'Chart.Types.xys' points: angles are not presevred in the new reference frame.
+data PathInfo a
+  = StartI
+  | LineI
+  | CubicI (Point a) (Point a)
+  | QuadI (Point a)
+  | ArcI (ArcInfo a)
   deriving (Show, Eq, Generic)
 
 -- | convert from a path info, start point, end point triple to a path text clause.
@@ -129,37 +128,44 @@
 -- - arc rotation is expressed as positive degrees for a clockwise rotation in SVG, and counter-clockwise in radians for chart-svg
 --
 -- - A positive y-direction is down for SVG and up for chart-svg
---
 toPathAbsolute ::
   -- | (info, start, end)
   (PathInfo Double, Point Double) ->
   -- | path text
   Text
-toPathAbsolute (StartI,p) = "M " <> pp p
-toPathAbsolute (LineI,p) = "L " <> pp p
+toPathAbsolute (StartI, p) = "M " <> pp p
+toPathAbsolute (LineI, p) = "L " <> pp p
 toPathAbsolute (CubicI c1 c2, next) =
-  "C " <>
-  pp c1 <> " " <>
-  pp c2 <> " " <>
-  pp next
+  "C "
+    <> pp c1
+    <> " "
+    <> pp c2
+    <> " "
+    <> pp next
 toPathAbsolute (QuadI control, next) =
-  "Q " <>
-  pp control <> " " <>
-  pp next
+  "Q "
+    <> pp control
+    <> " "
+    <> pp next
 toPathAbsolute (ArcI (ArcInfo (Point x y) phi' l sw), x2) =
-  "A " <>
-  show x <> " " <>
-  show y <> " " <>
-  show (-phi' * 180 / pi) <> " " <>
-  bool "0" "1" l <> " " <>
-  bool "0" "1" sw <> " " <>
-  pp x2
+  "A "
+    <> show x
+    <> " "
+    <> show y
+    <> " "
+    <> show (- phi' * 180 / pi)
+    <> " "
+    <> bool "0" "1" l
+    <> " "
+    <> bool "0" "1" sw
+    <> " "
+    <> pp x2
 
 -- | render a point (including a flip of the y dimension).
 pp :: Point Double -> Text
 pp (Point x y) =
-  showOr (FormatFixed (Just 4)) x <> "," <>
-  showOr (FormatFixed (Just 4)) (bool (-y) y (y==zero))
+  showOr (FormatFixed (Just 4)) x <> ","
+    <> showOr (FormatFixed (Just 4)) (bool (- y) y (y == zero))
 
 -- | convert an (info, point) list to an svg d path text.
 toPathAbsolutes :: [(PathInfo Double, Point Double)] -> Text
@@ -167,33 +173,32 @@
   where
     done = Text.intercalate " " . reverse
     begin = []
-    step ts (info, next) = toPathAbsolute (info, next):ts
+    step ts (info, next) = toPathAbsolute (info, next) : ts
 
 -- | Convert from PathInfo to PathCommand
 toPathCommand ::
   (PathInfo Double, Point Double) ->
   -- | path text
   PathCommand
-toPathCommand (StartI,p) = MoveTo OriginAbsolute [toV2 p]
-toPathCommand (LineI,p) = LineTo OriginAbsolute [toV2 p]
+toPathCommand (StartI, p) = MoveTo OriginAbsolute [toV2 p]
+toPathCommand (LineI, p) = LineTo OriginAbsolute [toV2 p]
 toPathCommand (CubicI c1 c2, p) = CurveTo OriginAbsolute [(toV2 c1, toV2 c2, toV2 p)]
 toPathCommand (QuadI c, p) = QuadraticBezier OriginAbsolute [(toV2 c, toV2 p)]
 toPathCommand (ArcI (ArcInfo (Point rx ry) phi' l sw), p) =
-  EllipticalArc OriginAbsolute [(rx,ry,phi',l,sw,toV2 p)]
+  EllipticalArc OriginAbsolute [(rx, ry, phi', l, sw, toV2 p)]
 
 toV2 :: Point a -> Linear.V2 a
 toV2 (Point x y) = Linear.V2 x y
 
-data StateInfo =
-  StateInfo
-  {
-    -- | previous position
+data StateInfo = StateInfo
+  { -- | previous position
     cur :: Point Double,
     -- | start point (to close out the path)
     start :: Point Double,
     -- | last control point
     infoControl :: Point Double
-  } deriving (Eq, Show, Generic)
+  }
+  deriving (Eq, Show, Generic)
 
 stateInfo0 :: StateInfo
 stateInfo0 = StateInfo zero zero zero
@@ -203,125 +208,128 @@
 -- flips the y-dimension of points.
 toInfo :: StateInfo -> SvgTree.PathCommand -> (StateInfo, [(PathInfo Double, Point Double)])
 toInfo s (MoveTo _ []) = (s, [])
-toInfo _ (MoveTo OriginAbsolute (x:xs)) = L.fold (L.Fold step begin (second reverse)) (fromV2 <$> xs)
+toInfo _ (MoveTo OriginAbsolute (x : xs)) = L.fold (L.Fold step begin (second reverse)) (fromV2 <$> xs)
   where
     x0 = fromV2 x
     begin = (StateInfo x0 x0 zero, [(StartI, x0)])
-    step (s, p) a = (s & #cur .~ a, (LineI, a):p)
-toInfo s (MoveTo OriginRelative (x:xs)) = L.fold (L.Fold step begin (second reverse)) (fromV2 <$> xs)
+    step (s, p) a = (s & #cur .~ a, (LineI, a) : p)
+toInfo s (MoveTo OriginRelative (x : xs)) = L.fold (L.Fold step begin (second reverse)) (fromV2 <$> xs)
   where
     x0 = s ^. #cur + fromV2 x
     begin = (StateInfo x0 x0 zero, [(StartI, x0)])
-    step (s, p) a = let a' = a + s ^. #cur in (s & #cur .~ a', (LineI, a'):p)
+    step (s, p) a = let a' = a + s ^. #cur in (s & #cur .~ a', (LineI, a') : p)
 toInfo s EndPath = (s, [(LineI, s ^. #start)])
-toInfo s (LineTo OriginAbsolute xs) = L.fold (L.Fold step (s,[]) (second reverse)) (fromV2 <$> xs)
+toInfo s (LineTo OriginAbsolute xs) = L.fold (L.Fold step (s, []) (second reverse)) (fromV2 <$> xs)
   where
-    step (s, p) a = (s & #cur .~ a, (LineI, a):p)
-toInfo s (LineTo OriginRelative xs) = L.fold (L.Fold step (s,[]) (second reverse)) (fromV2 <$> xs)
+    step (s, p) a = (s & #cur .~ a, (LineI, a) : p)
+toInfo s (LineTo OriginRelative xs) = L.fold (L.Fold step (s, []) (second reverse)) (fromV2 <$> xs)
   where
-    step (s, p) a = let a' = a + s ^. #cur in (s & #cur .~ a', (LineI, a'):p)
-toInfo s (HorizontalTo OriginAbsolute xs) = L.fold (L.Fold step (s,[]) (second reverse)) xs
+    step (s, p) a = let a' = a + s ^. #cur in (s & #cur .~ a', (LineI, a') : p)
+toInfo s (HorizontalTo OriginAbsolute xs) = L.fold (L.Fold step (s, []) (second reverse)) xs
   where
     step (s@(StateInfo (Point _ cy) _ _), p) a =
-      let a' = Point a cy in (s & #cur .~ a', (LineI, a'):p)
-toInfo s (HorizontalTo OriginRelative xs) = L.fold (L.Fold step (s,[]) (second reverse)) xs
+      let a' = Point a cy in (s & #cur .~ a', (LineI, a') : p)
+toInfo s (HorizontalTo OriginRelative xs) = L.fold (L.Fold step (s, []) (second reverse)) xs
   where
     step (s@(StateInfo (Point cx cy) _ _), p) a =
-      let a' = Point (a+cx) cy in (s & #cur .~ a', (LineI, a'):p)
-toInfo s (VerticalTo OriginAbsolute xs) = L.fold (L.Fold step (s,[]) (second reverse)) xs
+      let a' = Point (a + cx) cy in (s & #cur .~ a', (LineI, a') : p)
+toInfo s (VerticalTo OriginAbsolute xs) = L.fold (L.Fold step (s, []) (second reverse)) xs
   where
     step (s@(StateInfo (Point cx _) _ _), p) a =
-      let a' = Point cx a in (s & #cur .~ a', (LineI, a'):p)
-toInfo s (VerticalTo OriginRelative xs) = L.fold (L.Fold step (s,[]) (second reverse)) xs
+      let a' = Point cx a in (s & #cur .~ a', (LineI, a') : p)
+toInfo s (VerticalTo OriginRelative xs) = L.fold (L.Fold step (s, []) (second reverse)) xs
   where
     step (s@(StateInfo (Point cx cy) _ _), p) a =
-      let a' = Point cx (a+cy) in (s & #cur .~ a', (LineI, a'):p)
+      let a' = Point cx (a + cy) in (s & #cur .~ a', (LineI, a') : p)
 toInfo s (CurveTo OriginAbsolute xs) =
-  L.fold (L.Fold step (s,[]) (second reverse)) xs'
+  L.fold (L.Fold step (s, []) (second reverse)) xs'
   where
-    xs' = (\(c1,c2,x2) -> (fromV2 c1, fromV2 c2, fromV2 x2)) <$> xs
-    step (s, p) (c1,c2,x2) =
-          (s & #cur .~ x2 & #infoControl .~ c2, (CubicI c1 c2, x2):p)
+    xs' = (\(c1, c2, x2) -> (fromV2 c1, fromV2 c2, fromV2 x2)) <$> xs
+    step (s, p) (c1, c2, x2) =
+      (s & #cur .~ x2 & #infoControl .~ c2, (CubicI c1 c2, x2) : p)
 toInfo s (CurveTo OriginRelative xs) =
-  L.fold (L.Fold step (s,[]) (second reverse)) xs'
+  L.fold (L.Fold step (s, []) (second reverse)) xs'
   where
-    xs' = (\(c1,c2,x2) -> (fromV2 c1, fromV2 c2, fromV2 x2)) <$> xs
-    step (s, p) (c1,c2,x2) =
-          (s & #cur .~ (x2 + s ^. #cur) & #infoControl .~ (c2 + s ^. #cur), (CubicI (c1+ s ^. #cur) (c2 + s ^. #cur), x2 + s ^. #cur):p)
+    xs' = (\(c1, c2, x2) -> (fromV2 c1, fromV2 c2, fromV2 x2)) <$> xs
+    step (s, p) (c1, c2, x2) =
+      (s & #cur .~ (x2 + s ^. #cur) & #infoControl .~ (c2 + s ^. #cur), (CubicI (c1 + s ^. #cur) (c2 + s ^. #cur), x2 + s ^. #cur) : p)
 toInfo s (SmoothCurveTo OriginAbsolute xs) =
-  L.fold (L.Fold step (s,[]) (second reverse)) xs'
+  L.fold (L.Fold step (s, []) (second reverse)) xs'
   where
     xs' = bimap fromV2 fromV2 <$> xs
-    step (s, p) (c2,x2) =
-          (s & #cur .~ x2, (CubicI (s ^. #cur - (s ^. #infoControl - s^. #cur)) c2, x2):p)
+    step (s, p) (c2, x2) =
+      (s & #cur .~ x2, (CubicI (s ^. #cur - (s ^. #infoControl - s ^. #cur)) c2, x2) : p)
 toInfo s (SmoothCurveTo OriginRelative xs) =
-  L.fold (L.Fold step (s,[]) (second reverse)) xs'
+  L.fold (L.Fold step (s, []) (second reverse)) xs'
   where
     xs' = bimap fromV2 fromV2 <$> xs
-    step (s, p) (c2,x2) =
-          (s &
-           #cur .~ (x2 + s ^. #cur) &
-           #infoControl .~ (c2 + s ^. #cur),
-           (CubicI (s ^. #cur - (s ^. #infoControl - s^. #cur)) (c2 + s ^. #cur), x2 + s ^. #cur):p)
+    step (s, p) (c2, x2) =
+      ( s
+          & #cur .~ (x2 + s ^. #cur)
+          & #infoControl .~ (c2 + s ^. #cur),
+        (CubicI (s ^. #cur - (s ^. #infoControl - s ^. #cur)) (c2 + s ^. #cur), x2 + s ^. #cur) : p
+      )
 toInfo s (QuadraticBezier OriginAbsolute xs) =
-  L.fold (L.Fold step (s,[]) (second reverse)) xs'
+  L.fold (L.Fold step (s, []) (second reverse)) xs'
   where
     xs' = bimap fromV2 fromV2 <$> xs
     step (s, p) (c1, x2) =
-          (s &
-           #cur .~ x2 &
-           #infoControl .~ c1,
-           (QuadI c1, x2):p)
+      ( s
+          & #cur .~ x2
+          & #infoControl .~ c1,
+        (QuadI c1, x2) : p
+      )
 toInfo s (QuadraticBezier OriginRelative xs) =
-  L.fold (L.Fold step (s,[]) (second reverse)) xs'
+  L.fold (L.Fold step (s, []) (second reverse)) xs'
   where
     xs' = bimap fromV2 fromV2 <$> xs
-    step (s, p) (c1,x2) =
-          (s & #cur .~ x2 & #infoControl .~ (c1 + s ^. #cur), (QuadI (c1 + s ^. #cur), x2 + s ^. #cur):p)
+    step (s, p) (c1, x2) =
+      (s & #cur .~ x2 & #infoControl .~ (c1 + s ^. #cur), (QuadI (c1 + s ^. #cur), x2 + s ^. #cur) : p)
 toInfo s (SmoothQuadraticBezierCurveTo OriginAbsolute xs) =
-  L.fold (L.Fold step (s,[]) (second reverse)) xs'
+  L.fold (L.Fold step (s, []) (second reverse)) xs'
   where
     xs' = fromV2 <$> xs
     step (s, p) x2 =
-          (s &
-           #cur .~ x2 &
-           #infoControl .~ (s ^. #cur - (s ^. #infoControl - s ^. #cur)),
-           (QuadI (s ^. #cur - (s ^. #infoControl - s^. #cur)), x2):p)
+      ( s
+          & #cur .~ x2
+          & #infoControl .~ (s ^. #cur - (s ^. #infoControl - s ^. #cur)),
+        (QuadI (s ^. #cur - (s ^. #infoControl - s ^. #cur)), x2) : p
+      )
 toInfo s (SmoothQuadraticBezierCurveTo OriginRelative xs) =
-  L.fold (L.Fold step (s,[]) (second reverse)) xs'
+  L.fold (L.Fold step (s, []) (second reverse)) xs'
   where
     xs' = fromV2 <$> xs
     step (s, p) x2 =
-          (s &
-           #cur .~ (x2 + s ^. #cur) &
-           #infoControl .~ (s ^. #cur - (s ^. #infoControl - s ^. #cur)),
-           (QuadI (s ^. #cur - (s ^. #infoControl - s^. #cur)), x2 + s ^. #cur):p)
+      ( s
+          & #cur .~ (x2 + s ^. #cur)
+          & #infoControl .~ (s ^. #cur - (s ^. #infoControl - s ^. #cur)),
+        (QuadI (s ^. #cur - (s ^. #infoControl - s ^. #cur)), x2 + s ^. #cur) : p
+      )
 toInfo s (EllipticalArc OriginAbsolute xs) =
-  L.fold (L.Fold step (s,[]) (second reverse)) xs'
+  L.fold (L.Fold step (s, []) (second reverse)) xs'
   where
-    xs' = (\(x,y,r,l,sw,x2) -> (x,y,r,l,sw,fromV2 x2)) <$> xs
-    step (s, p) a@(_,_,_,_,_,x2) =
-          (s & #cur .~ x2, (fromPathEllipticalArc (s ^. #cur) a, x2):p)
+    xs' = (\(x, y, r, l, sw, x2) -> (x, y, r, l, sw, fromV2 x2)) <$> xs
+    step (s, p) a@(_, _, _, _, _, x2) =
+      (s & #cur .~ x2, (fromPathEllipticalArc (s ^. #cur) a, x2) : p)
 toInfo s (EllipticalArc OriginRelative xs) =
-  L.fold (L.Fold step (s,[]) (second reverse)) xs'
+  L.fold (L.Fold step (s, []) (second reverse)) xs'
   where
-    xs' = (\(x,y,r,l,sw,x2) -> (x,y,r,l,sw,fromV2 x2)) <$> xs
-    step (s, p) a@(_,_,_,_,_,x2) =
-      let x2' = x2 + s ^. #cur in
-          (s & #cur .~ x2', (fromPathEllipticalArc (s ^. #cur) a, x2'):p)
+    xs' = (\(x, y, r, l, sw, x2) -> (x, y, r, l, sw, fromV2 x2)) <$> xs
+    step (s, p) a@(_, _, _, _, _, x2) =
+      let x2' = x2 + s ^. #cur
+       in (s & #cur .~ x2', (fromPathEllipticalArc (s ^. #cur) a, x2') : p)
 
 fromPathEllipticalArc :: Point a -> (a, a, a, Bool, Bool, Point a) -> PathInfo a
 fromPathEllipticalArc _ (x, y, r, l, s, _) = ArcI (ArcInfo (Point x y) r l s)
 
 fromV2 :: (Subtractive a) => Linear.V2 a -> Point a
-fromV2 (Linear.V2 x y) = Point x (-y)
+fromV2 (Linear.V2 x y) = Point x (- y)
 
 -- | Convert from a path command list to a PathA specification
---
 toPathXYs :: [SvgTree.PathCommand] -> [(PathInfo Double, Point Double)]
 toPathXYs [] = []
 toPathXYs xs =
-  snd (foldl' (\(x,l) a -> second (l<>) $ toInfo x a) (stateInfo0,[]) xs)
+  snd (foldl' (\(x, l) a -> second (l <>) $ toInfo x a) (stateInfo0, []) xs)
 
 -- | convert cubic position to path info.
 singletonCubic :: CubicPosition Double -> [(PathInfo Double, Point Double)]
@@ -348,14 +356,13 @@
 
 -- | convert path info to an ArcPosition.
 toSingletonArc :: [(PathInfo Double, Point Double)] -> Maybe (ArcPosition Double)
-toSingletonArc ((StartI, s):(ArcI i, e):_) = Just $ ArcPosition s e i
+toSingletonArc ((StartI, s) : (ArcI i, e) : _) = Just $ ArcPosition s e i
 toSingletonArc _ = Nothing
 
 -- * Arc types
+
 -- | Information about an individual arc path.
---
-data ArcInfo a =
-  ArcInfo
+data ArcInfo a = ArcInfo
   { -- | ellipse radii
     radii :: Point a,
     -- | rotation of the ellipse. positive means counter-clockwise (which is different to SVG).
@@ -363,22 +370,21 @@
     large :: Bool,
     -- | sweep means clockwise
     clockwise :: Bool
-  } deriving (Eq, Show, Generic)
+  }
+  deriving (Eq, Show, Generic)
 
 -- | Specification of an Arc using positional referencing as per SVG standard.
-data ArcPosition a =
-  ArcPosition
+data ArcPosition a = ArcPosition
   { posStart :: Point a,
     posEnd :: Point a,
     posInfo :: ArcInfo a
-  } deriving (Eq, Show, Generic)
+  }
+  deriving (Eq, Show, Generic)
 
 -- | Arc specification based on centroidal interpretation.
 --
 -- See: https://www.w3.org/TR/SVG/implnote.html#ArcConversionEndpointToCenter
---
-data ArcCentroid a =
-  ArcCentroid
+data ArcCentroid a = ArcCentroid
   { -- | ellipse center
     centroid :: Point a,
     -- | ellipse radii
@@ -389,7 +395,8 @@
     ang0 :: a,
     -- | difference between ending point angle and starting point angle
     angdiff :: a
-  } deriving (Eq, Show, Generic)
+  }
+  deriving (Eq, Show, Generic)
 
 -- | convert from an ArcPosition spec to ArcCentroid spec.
 --
@@ -401,25 +408,27 @@
 arcCentroid :: (FromInteger a, Ord a, TrigField a, ExpField a) => ArcPosition a -> ArcCentroid a
 arcCentroid (ArcPosition p1@(Point x1 y1) p2@(Point x2 y2) (ArcInfo rad phi large clockwise)) = ArcCentroid c (Point rx ry) phi ang1 angd
   where
-    (Point x1' y1') = rotateP (-phi) ((p1 - p2) /. two)
+    (Point x1' y1') = rotateP (- phi) ((p1 - p2) /. two)
     (Point rx' ry') = rad
-    l = x1'**2/rx'**2 + y1'**2/ry'**2
-    (rx,ry) = bool (rx',ry') (rx'*sqrt l, ry'*sqrt l) (l > 1)
-    snumer = max 0 $ (rx*rx*ry*ry) - (rx*rx*y1'*y1') - (ry*ry*x1'*x1')
-    s = bool -1 1 (large == clockwise) * sqrt
-      (snumer / (rx*rx*y1'*y1' + ry*ry*x1'*x1'))
-    cx' = s *  rx * y1' / ry
-    cy' = s * (-ry) * x1' / rx
+    l = x1' ** 2 / rx' ** 2 + y1' ** 2 / ry' ** 2
+    (rx, ry) = bool (rx', ry') (rx' * sqrt l, ry' * sqrt l) (l > 1)
+    snumer = max 0 $ (rx * rx * ry * ry) - (rx * rx * y1' * y1') - (ry * ry * x1' * x1')
+    s =
+      bool -1 1 (large == clockwise)
+        * sqrt
+          (snumer / (rx * rx * y1' * y1' + ry * ry * x1' * x1'))
+    cx' = s * rx * y1' / ry
+    cy' = s * (- ry) * x1' / rx
     cx = (x1 + x2) / 2 + cos phi * cx' - sin phi * cy'
     cy = (y1 + y2) / 2 + sin phi * cx' + cos phi * cy'
     c = Point cx cy
-    ang1 = angle (Point (-(cx'-x1')/rx) (-(cy'-y1')/ry))
-    ang2 = angle (Point (-(cx'+x1')/rx) (-(cy'+y1')/ry))
+    ang1 = angle (Point (- (cx' - x1') / rx) (- (cy' - y1') / ry))
+    ang2 = angle (Point (- (cx' + x1') / rx) (- (cy' + y1') / ry))
     angd' = ang2 - ang1
     angd =
-      bool 0 (2*pi) (not clockwise && angd'<0) +
-      bool 0 (-2*pi) (clockwise && angd'>0) +
-      angd'
+      bool 0 (2 * pi) (not clockwise && angd' < 0)
+        + bool 0 (-2 * pi) (clockwise && angd' > 0)
+        + angd'
 
 -- | convert from an ArcCentroid to an ArcPosition specification.
 --
@@ -431,13 +440,12 @@
 -- - angle diff is pi and large is True
 --
 -- - radii are less than they should be and thus get scaled up.
---
 arcPosition :: (Ord a, Signed a, TrigField a) => ArcCentroid a -> ArcPosition a
 arcPosition (ArcCentroid c r phi ang1 angd) =
   ArcPosition p1 p2 (ArcInfo r phi large clockwise)
   where
     p1 = ellipse c r phi ang1
-    p2 = ellipse c r phi (ang1+angd)
+    p2 = ellipse c r phi (ang1 + angd)
     large = abs angd > pi
     clockwise = angd < zero
 
@@ -455,7 +463,6 @@
 -- > c + (rotate phi |. (r * ray theta))
 --
 -- See also: [wolfram](https://mathworld.wolfram.com/Ellipse.html)
---
 ellipse :: (Direction b a, Affinity b a, TrigField a) => b -> b -> a -> a -> b
 ellipse c r phi theta = c + (rotate phi |. (r * ray theta))
 
@@ -468,21 +475,22 @@
 arcBox p = space1 pts
   where
     (ArcCentroid c r phi ang0 angd) = arcCentroid p
-    (x',y') = arcDerivs r phi
+    (x', y') = arcDerivs r phi
     angr = ang0 ... (ang0 + angd) :: Range Double
     angs =
-      filter (|.| angr)
-      [ x',
-        x' - 2 * pi,
-        x'+pi,
-        x'-pi,
-        y',
-        y' - 2 * pi,
-        y'+pi,
-        y'-pi,
-        ang0,
-        ang0+angd
-      ]
+      filter
+        (|.| angr)
+        [ x',
+          x' - 2 * pi,
+          x' + pi,
+          x' - pi,
+          y',
+          y' - 2 * pi,
+          y' + pi,
+          y' - pi,
+          ang0,
+          ang0 + angd
+        ]
     pts = ellipse c r phi <$> angs
 
 -- | potential arc turning points.
@@ -492,32 +500,32 @@
 arcDerivs :: Point Double -> Double -> (Double, Double)
 arcDerivs (Point rx ry) phi = (thetax1, thetay1)
   where
-    thetax1 = atan2 (-sin phi * ry) (cos phi * rx)
+    thetax1 = atan2 (- sin phi * ry) (cos phi * rx)
     thetay1 = atan2 (cos phi * ry) (sin phi * rx)
 
 -- * bezier
+
 -- | Quadratic bezier curve expressed in positional terms.
---
-data QuadPosition a =
-  QuadPosition
+data QuadPosition a = QuadPosition
   { -- | starting point
     qposStart :: Point a,
     -- | ending point
     qposEnd :: Point a,
     -- | control point
     qposControl :: Point a
-  } deriving (Eq, Show, Generic)
+  }
+  deriving (Eq, Show, Generic)
 
 -- | Quadratic bezier curve with control point expressed in polar terms normalised to the start - end line.
-data QuadPolar a =
-  QuadPolar
+data QuadPolar a = QuadPolar
   { -- | starting point
     qpolStart :: Point a,
     -- | ending point
     qpolEnd :: Point a,
     -- | control point in terms of distance from and angle to the qp0 - qp2 line
     qpolControl :: Polar a a
-  } deriving (Eq, Show, Generic)
+  }
+  deriving (Eq, Show, Generic)
 
 -- | Convert from a positional to a polar representation of a cubic bezier.
 --
@@ -547,20 +555,20 @@
 -- Point 0.9999999933333332 -0.33333333333333326
 quadBezier :: (ExpField a, FromInteger a) => QuadPosition a -> a -> Point a
 quadBezier (QuadPosition start end control) theta =
-  (1 - theta)^2 .* start +
-  2 * (1-theta) * theta .* control +
-  theta^2 .* end
+  (1 - theta) ^ 2 .* start
+    + 2 * (1 - theta) * theta .* control
+    + theta ^ 2 .* end
 
 -- | QuadPosition turning points.
 --
 -- >>> quadDerivs (QuadPosition (Point 0 0) (Point 1 1) (Point 2 -1))
 -- [0.6666666666666666,0.3333333333333333]
 quadDerivs :: QuadPosition Double -> [Double]
-quadDerivs (QuadPosition start end control) = [x',y']
+quadDerivs (QuadPosition start end control) = [x', y']
   where
     (Point detx dety) = start - 2 .* control + end
-    x' = bool ((_x start - _x control)/detx) (2 * (_x control - _x start)) (detx==0)
-    y' = bool ((_y start - _y control)/dety) (2 * (_y control - _y start)) (dety==0)
+    x' = bool ((_x start - _x control) / detx) (2 * (_x control - _x start)) (detx == 0)
+    y' = bool ((_y start - _y control) / dety) (2 * (_y control - _y start)) (dety == 0)
 
 -- | Bounding box for a QuadPosition
 --
@@ -570,13 +578,12 @@
 quadBox p = space1 pts
   where
     ts = quadDerivs p
-    pts = quadBezier p <$> ([0,1] <> ts)
+    pts = quadBezier p <$> ([0, 1] <> ts)
 
 -- | cubic bezier curve
 --
 -- Note that the ordering is different to the svg standard.
-data CubicPosition a =
-  CubicPosition
+data CubicPosition a = CubicPosition
   { -- | starting point
     cposStart :: Point a,
     -- | ending point
@@ -585,11 +592,11 @@
     cposControl1 :: Point a,
     -- | control point 2
     cposControl2 :: Point a
-  } deriving (Eq, Show, Generic)
+  }
+  deriving (Eq, Show, Generic)
 
 -- | A polar representation of a cubic bezier with control points expressed as polar and normalised to the start - end line.
-data CubicPolar a =
-  CubicPolar
+data CubicPolar a = CubicPolar
   { -- | starting point
     cpolStart :: Point a,
     -- | ending point
@@ -598,7 +605,8 @@
     cpolControl1 :: Polar a a,
     -- | control point in terms of distance from and angle to the start end line
     cpolControl2 :: Polar a a
-  } deriving (Eq, Show, Generic)
+  }
+  deriving (Eq, Show, Generic)
 
 -- | Convert from a positional to a polar representation of a cubic bezier.
 --
@@ -633,46 +641,50 @@
 -- Point 0.6767766952966369 1.2071067811865475
 cubicBezier :: (ExpField a, FromInteger a) => CubicPosition a -> a -> Point a
 cubicBezier (CubicPosition start end control1 control2) theta =
-  (1 - theta)^3 .* start +
-  3 * (1-theta)^2 * theta .* control1 +
-  3 * (1-theta) * theta^2 .* control2 +
-  theta^3 .* end
+  (1 - theta) ^ 3 .* start
+    + 3 * (1 - theta) ^ 2 * theta .* control1
+    + 3 * (1 - theta) * theta ^ 2 .* control2
+    + theta ^ 3 .* end
 
 -- | Turning point positions for a CubicPosition (0,1 or 2)
 --
 -- >>> cubicDerivs (CubicPosition (Point 0 0) (Point 1 1) (Point 1 -1) (Point 0 2))
 -- [0.8535533905932737,0.14644660940672624,0.5]
 cubicDerivs :: CubicPosition Double -> [Double]
-cubicDerivs (CubicPosition (Point c0x c0y) (Point c3x c3y)
-             (Point c1x c1y) (Point c2x c2y)) =
-  B.bezierHoriz b <> B.bezierVert b
-  where
-    b =
-      B.CubicBezier
-      (B.Point c0x c0y)
-      (B.Point c1x c1y)
-      (B.Point c2x c2y)
-      (B.Point c3x c3y)
+cubicDerivs
+  ( CubicPosition
+      (Point c0x c0y)
+      (Point c3x c3y)
+      (Point c1x c1y)
+      (Point c2x c2y)
+    ) =
+    B.bezierHoriz b <> B.bezierVert b
+    where
+      b =
+        B.CubicBezier
+          (B.Point c0x c0y)
+          (B.Point c1x c1y)
+          (B.Point c2x c2y)
+          (B.Point c3x c3y)
 
 -- | Bounding box for a CubicPosition
 --
 -- >>> cubicBox (CubicPosition (Point 0 0) (Point 1 1) (Point 1 -1) (Point 0 2))
 -- Rect 0.0 1.0 -0.20710678118654752 1.2071067811865475
---
 cubicBox :: CubicPosition Double -> Rect Double
 cubicBox p = space1 pts
   where
     ts = cubicDerivs p
-    pts = cubicBezier p <$>
-          filter
+    pts =
+      cubicBezier p
+        <$> filter
           (|.| Range 0 1)
-          ([0,1] <> ts)
+          ([0, 1] <> ts)
 
 -- | Bounding box for a list of path XYs.
---
 pathBoxes :: [(PathInfo Double, Point Double)] -> Maybe (Rect Double)
 pathBoxes [] = Nothing
-pathBoxes (x:xs) =
+pathBoxes (x : xs) =
   L.fold (L.Fold step begin (Just . snd)) xs
   where
     begin :: (Point Double, Rect Double)
@@ -684,7 +696,6 @@
     step (start, r) a = (snd a, pathBox start a <> r)
 
 -- | Bounding box for a path info, start and end Points.
---
 pathBox :: Point Double -> (PathInfo Double, Point Double) -> Rect Double
 pathBox start (info, end) =
   case info of
diff --git a/test/test.hs b/test/test.hs
--- a/test/test.hs
+++ b/test/test.hs
@@ -15,5 +15,7 @@
     "src/Chart/Bar.hs",
     "src/Chart/Render.hs",
     "src/Chart/Surface.hs",
-    "src/Chart/Examples.hs"
+    "src/Chart/Examples.hs",
+    "src/Data/Colour.hs",
+    "src/Chart/Reanimate.hs"
   ]