initial commit

app/Main.hs

@@ -0,0 +1,37 @@
+{-# 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
+
+  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
+            layout = layout_title .~ "slope field"
+                   $ layout_plots .~ [vectors]
+                   $ def
+
+            vectors = plotVectorField
+                    $ plot_vectors_values .~ field
+                    $ plot_vectors_scale .~ 0
+                    $ plot_vectors_style . vector_head_style . point_radius .~ 0
+                    $ def
+
+    renderableToFile def "slope-field.png" chart
+    putStrLn "created file slope-field.png"
+    return ()