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Mere interaction with a user through +a computer network, with no transfer of a copy, diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/app/Main.hs b/app/Main.hs new file mode 100644 --- /dev/null +++ b/app/Main.hs @@ -0,0 +1,43 @@ +{-# LANGUAGE ScopedTypeVariables #-} + +module Main where + import Lib + import System.IO + import Graphics.Rendering.Chart + import Graphics.Rendering.Chart.Backend.Cairo + import Control.Lens + import Data.Default.Class + import Data.Colour.SRGB + import Data.Colour + + main :: IO () + main = do + putStrLn "dy/dx = " + math <- getLine + putStrLn "range - format: (lower, upper): " + (lower, upper) :: (Int, Int) <- read <$> getLine + putStrLn "estimation size: " + s <- read <$> getLine + + let pts = points (lower, upper) + field = slopeField math pts s + + let chart = toRenderable layout + where + color = opaque (sRGB 0.3 0.3 1) + + layout = layout_title .~ "slope field" + $ layout_plots .~ [vectors] + $ def + + vectors = plotVectorField + $ plot_vectors_values .~ field + $ plot_vectors_scale .~ 1 + $ plot_vectors_grid .~ [] + $ plot_vectors_style . vector_head_style . point_color .~ color + $ plot_vectors_style . vector_line_style . line_color .~ color + $ def + + renderableToFile def "slope-field.png" chart + putStrLn "created file slope-field.png" + return () diff --git a/slope-field.cabal b/slope-field.cabal new file mode 100644 --- /dev/null +++ b/slope-field.cabal @@ -0,0 +1,39 @@ +name: slope-field +version: 0.1.0.1 +synopsis: Visualize mathematical function's slope fields +description: Visualize mathematical function's slope fields +homepage: https://github.com/mdibaiee/slope-field +license: GPL-3 +license-file: LICENSE +author: Mahdi Dibaiee +maintainer: mdibaiee@aol.com +copyright: 2016 Mahdi Dibaiee +category: Web +build-type: Simple +-- extra-source-files: +cabal-version: >=1.10 + +library + hs-source-dirs: src + exposed-modules: Lib + build-depends: base >= 4.7 && < 5 + , mathexpr >= 0.3.0.0 + , data-default-class + default-language: Haskell2010 + +executable slope-field + hs-source-dirs: app + main-is: Main.hs + ghc-options: -threaded -rtsopts -with-rtsopts=-N + build-depends: base + , slope-field + , Chart + , Chart-cairo + , lens + , data-default-class + , colour + default-language: Haskell2010 + +source-repository head + type: git + location: https://github.com/mdibaiee/slope-field diff --git a/src/Lib.hs b/src/Lib.hs new file mode 100644 --- /dev/null +++ b/src/Lib.hs @@ -0,0 +1,26 @@ +module Lib + ( points + , slopeField + ) where + import Numeric.MathExpr + import Data.Default.Class + + type Range = (Int, Int) + + points :: Range -> [(Double, Double)] + points (lower, upper) = + let range = [lower..upper] + in [ (fromIntegral x, fromIntegral y) | x <- range, y <- range ] + + slopeField :: String -> [(Double, Double)] -> Double -> [((Double, Double), (Double, Double))] + slopeField math pts diff = + let d x y = evaluate def math [("x", x), ("y", y)] + half = diff / 2 + res = map (\(x, y) -> ((x - half, y), (half, d x y * diff))) pts + inf = 1/0 + noinf = filter (\((x0, y0), (x, y)) -> x < inf && y < inf && x > -inf && y > -inf) res + (minx, miny) = head pts + (maxx, maxy) = last pts + limitX = min maxx . max minx + limitY = min maxy . max miny + in map (\((x0, y0), (x1, y1)) -> ((limitX x0, limitY y0), (limitX x1, limitY y1))) noinf