diff --git a/GoogleChart.cabal b/GoogleChart.cabal --- a/GoogleChart.cabal +++ b/GoogleChart.cabal @@ -1,6 +1,6 @@ Cabal-Version: >= 1.2 Name: GoogleChart -Version: 0.1 +Version: 0.2 Synopsis: Generate web-based charts using the Google Chart API Category: Graphics License: BSD3 diff --git a/Graphics/Google/Chart.hs b/Graphics/Google/Chart.hs --- a/Graphics/Google/Chart.hs +++ b/Graphics/Google/Chart.hs @@ -25,6 +25,17 @@ This produces: +Remaining features to implement: + +- lxy line charts + +- chbh bar charts + +- scatter plots + +- background\/fill colors + +- all style attributes -} module Graphics.Google.Chart ( @@ -35,11 +46,22 @@ setSize, setTitle, setTitleOpts, setData, -- ** Chart data -- | There are multiple options for encoding chart data. See - -- for more details. + -- for more details on + -- the tradeoffs of the different encoding options. ChartData, encodeDataSimple, encodeDataText, encodeDataExtended, + setDataColors, + -- * Chart features + -- ** Legends LegendChart, setLegend, + -- ** Axis labels + -- | The order of elements in the lists passed to these functions matter: + -- If the first 'AxisType' passed to 'setAxisTypes' is 'AxisBottom', then + -- the first set of labels passed to 'setAxisLabels' refers to that bottom + -- axis. + AxisLabelChart, setAxisTypes, AxisType(..), setAxisLabels, + setAxisLabelPositions, setAxisRanges, AxisAlignment(..), setAxisStyles, -- * Specific chart types -- ** Line charts @@ -49,21 +71,27 @@ PieChart, newPieChart, PieStyle(..), setLabels, -- ** Bar charts - BarChart, newBarChart, Orientation(..), BarStyle(..) + BarChart, newBarChart, Orientation(..), BarStyle(..), + + -- ** Venn diagrams + VennDiagram, newVennDiagram ) where import Data.Char (chr, ord) import Data.List (intercalate) import Numeric (showHex) --- | Bar - +-- | URL-encode a string. urlEnc str = concatMap enc str where - enc c | c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z' = [c] - | c >= '0' && c <= '9' = [c] - | c == '-' || c == '_' || c == '.' || c == '~' = [c] - | c == ' ' = "+" + enc c | c >= 'A' && c <= 'Z' = [c] + | c >= 'a' && c <= 'z' = [c] + | c >= '0' && c <= '9' = [c] + | c `elem` safe = [c] + | c == ' ' = "+" | otherwise = '%':(showHex (ord c) "") + -- Argh, different resources differ on which characters need escaping. + -- This is likely wrong. + safe = "$-_.!*'(),|:" -- All charts are internally represented as a list of (key,value) pairs. -- We could switch this to Data.Map if it matters. @@ -104,10 +132,10 @@ -- |All the encoding methods produce 'ChartData', which is usable by 'setData'. newtype ChartData = ChartData String deriving Show --- |Encode data using the \"simple\" encoding. This produces minimal URLs but --- doesn't have as much resolution. Input values must be in the range @0 <= x --- <= 61@. Values outside the valid input range will be considered missing --- data. +-- |Encode data using the \"simple\" encoding, which maps each input value +-- to a single letter in the URL. This produces minimal URLs but doesn't have +-- as lot of resolution. Input values must be in the range @0 <= x <= 61@. +-- Values outside the valid input range will be considered missing data. encodeDataSimple :: [[Int]] -> ChartData encodeDataSimple datas = ChartData $ "s:" ++ intercalate "," (map (map enc) datas) where @@ -116,26 +144,117 @@ | i >= 52 && i <= 61 = chr (ord '0' + (i - 52)) | otherwise = '_' --- |Encode data using the \"text\" encoding. XXX unimplemented. -encodeDataText :: [[Int]] -> ChartData -encodeDataText = undefined +-- |Encode data using the \"text\" encoding, which maps each input value to +-- its string representation (e.g. \"3.4\") in the URL. This has more +-- resolution than simple encoding but produces larger URLs. Input values must +-- be in the range @0 <= x <= 100@. Values outside the valid input range will +-- be considered missing data. Values with more than one decimal place of +-- resolution will be rounded. +encodeDataText :: RealFrac a => [[a]] -> ChartData +-- I chose RealFrac because it's necessary for floor; what is appropriate here? +-- The input must effectively be fixed-point. +encodeDataText datas = + ChartData $ "t:" ++ intercalate "|" (map encData datas) where + encData = intercalate "," . map encDatum + encDatum i | i >= 0 && i <= 100 = showDecimal i + | otherwise = "-1" + showDecimal :: RealFrac a => a -> String + showDecimal i = show (fromIntegral (round (i * 10.0)) / 10.0) --- |Encode data using the \"extended\" encoding. XXX unimplemented. +-- |Encode data using the \"extended\" encoding, which maps each input value +-- to a two-character pair in base 64. This has more resolution than text +-- encoding and is more compact. Input values must be in the range @0 <= x <= +-- 4095@. Values outside the valid input range will be considered missing +-- data. encodeDataExtended :: [[Int]] -> ChartData -encodeDataExtended = undefined +encodeDataExtended datas = + ChartData $ "e:" ++ intercalate "," (map (concatMap encDatum) datas) where + encDatum i | i >= 0 && i < 4096 = let (a, b) = i `quotRem` 64 in + [encChar a, encChar b] + | otherwise = "__" + encChar i | i >= 0 && i <= 25 = chr (ord 'A' + i) + | i >= 26 && i <= 51 = chr (ord 'a' + (i - 26)) + | i >= 52 && i <= 61 = chr (ord '0' + (i - 52)) + | i == 62 = '-' + | i == 63 = '.' +-- |Set data set colors. The nth color specified here colors the nth data +-- set in the 'ChartData' passed to 'setData'. See +-- for more +-- information. +setDataColors :: Chart c => [String] -> c -> c +setDataColors colors = setParam "chco" (intercalate "," colors) + -- |LegendChart represents charts that can display legends with 'setLegend'. -class Chart c => LegendChart c where - -- |Set the legend for the corresponding data sets. The colors are taken - -- from the data set colors. - setLegend :: [String] -> c -> c - setLegend strs = setParam "chdl" (intercalate "|" strs) +class Chart c => LegendChart c +-- |Set the legend for the corresponding data sets. The colors are taken +-- from the data set colors. +setLegend :: LegendChart c => [String] -> c -> c +setLegend strs = setParam "chdl" (intercalate "|" strs) +-- |AxisLabelChart represents charts that can display axis labels. +class Chart c => AxisLabelChart c + +-- |Where to display an axis. +data AxisType = AxisBottom | AxisTop | AxisLeft | AxisRight + +-- |Set which axes to display. Repeating an 'AxisType' produces multiple +-- sets of labels on that axis. +setAxisTypes :: AxisLabelChart c => [AxisType] -> c -> c +setAxisTypes axes = setParam "chxt" (intercalate "," (map axisChar axes)) where + axisChar AxisBottom = "x" + axisChar AxisTop = "t" + axisChar AxisLeft = "y" + axisChar AxisRight = "r" + +-- |Set axis labels. The nth list of strings in the argument sets the labels +-- for the nth axis specified with 'setAxisTypes'. An empty list of strings +-- skips labelling the corresponding axis. +setAxisLabels :: AxisLabelChart c => [[String]] -> c -> c +setAxisLabels axislabels = + setParam "chxl" (intercalate "|" (zipWith axisLabel [0..] axislabels)) where + axisLabel :: Int -> [String] -> String + axisLabel _ [] = "" + axisLabel index labels = show index ++ ":|" ++ intercalate "|" labels + +-- |Set axis label positions. The nth list of Ints in the argument sets the +-- positions for the nth axis specified with 'setAxisTypes'. An empty list +-- skips setting position for the corresponding axis. +setAxisLabelPositions :: AxisLabelChart c => [[Int]] -> c -> c +setAxisLabelPositions positions = + setParam "chxp" (intercalate "|" (zipWith axisPosn [0..] positions)) where + axisPosn _ [] = "" + axisPosn index xs = intercalate "," (map show (index:xs)) + +-- |Set axis ranges. The nth pair of Ints in the argument sets the range +-- for the nth axis specified with 'setAxisTypes'. +setAxisRanges :: AxisLabelChart c => [(Int,Int)] -> c -> c +setAxisRanges ranges = + setParam "chxr" (intercalate "|" (zipWith axisRange [0..] ranges)) where + axisRange index (min,max) = intercalate "," (map show [index,min,max]) + +-- |Text alignment for labels on an axis. +data AxisAlignment = AlignLeft | AlignCenter | AlignRight + +-- |Set axis styles. The nth element in the argument sets the style for the +-- nth axis specified with 'setAxisTypes'. Each style is a tuple of +-- (color, font size, text alignment). +setAxisStyles :: AxisLabelChart c => [(String,Int,AxisAlignment)] -> c -> c +setAxisStyles styles = + setParam "chxs" (intercalate "|" (zipWith axisStyle [0..] styles)) where + axisStyle index (color, size, align) = + intercalate "," [show index, color, show size, alignString align] + alignString AlignLeft = "-1" + alignString AlignCenter = "0" + alignString AlignRight = "1" + + newtype LineChart = LineChart Params instance Chart LineChart where params (LineChart p) = p fromParams = LineChart instance LegendChart LineChart +instance AxisLabelChart LineChart newLineChart :: LineChart newLineChart = fromParams [("cht","lc")] @@ -149,6 +268,7 @@ newPieChart Pie2D = fromParams [("cht","p")] newPieChart Pie3D = fromParams [("cht","p3")] +-- |Set labels for the different data points on the chart. -- Specify missing values by passing an empty string. setLabels :: [String] -> PieChart -> PieChart setLabels labels = setParam "chl" $ intercalate "|" labels @@ -158,6 +278,7 @@ params (BarChart p) = p fromParams = BarChart instance LegendChart BarChart +instance AxisLabelChart BarChart data Orientation = Horizontal | Vertical data BarStyle = Stacked | Grouped newBarChart :: Orientation -> BarStyle -> BarChart @@ -167,3 +288,16 @@ oLetter Vertical = 'v' sLetter Stacked = 's' sLetter Grouped = 'g' + +-- |Venn diagram data is specified in a particular format. There should be +-- exactly seven data values, which represent, in order: +-- circle A size, circle B size, circle C size, +-- A\/B overlap, A\/C overlap, B\/C overlap, +-- A\/B\/C overlap. +newtype VennDiagram = VennDiagram Params +instance Chart VennDiagram where + params (VennDiagram p) = p + fromParams = VennDiagram +instance LegendChart VennDiagram +newVennDiagram :: VennDiagram +newVennDiagram = fromParams [("cht", "v")]