hist-demo.hs

-- Copyright © 2016 Bart Massey

-- Chart Histogram demo

import Control.Lens
import Data.Default.Class
import Graphics.Rendering.Chart
import Graphics.Rendering.Chart.Backend.Cairo

pdfRender :: String -> Renderable a -> IO ()
pdfRender name r = do
    _ <- renderableToFile (fo_format .~ PDF $ def) name r
    return ()

demoData :: [Double]
demoData = concat $ zipWith replicate [5, 4, 3, 7] [0..3]

plotDemoHist :: Renderable (LayoutPick Double Int Int)
plotDemoHist = do
  let histPlot =
          histToPlot $
          plot_hist_values .~  demoData $
          plot_hist_bins .~ 4 $
          defaultPlotHist
  let histLayout =
          layout_x_axis .~ (laxis_title .~ "value" $ def) $
          layout_y_axis .~ (laxis_title .~ "frequency" $ def) $
          layout_plots .~ [histPlot] $
          def
  layoutToRenderable histLayout

main :: IO ()
main =
  pdfRender "demo-hist.pdf" plotDemoHist