example 5

This chart:

was produced by this code:

import Graphics.Rendering.Chart.Easy
import Graphics.Rendering.Chart.Backend.Cairo


values :: [ (String,Double,Bool) ]
values = [ ("Mexico City",19.2,False), ("Mumbai",12.9,False), ("Sydney",4.3,False), ("London",8.3,False), ("New York",8.2,True) ]

pitem (s,v,o) = pitem_value .~ v
              $ pitem_label .~ s
              $ pitem_offset .~ (if o then 25 else 0)
              $ def

main = toFile def "example5_big.png" $ do
  pie_title .= "Relative Populations"
  pie_plot . pie_data .= map pitem values

Here is equivalent code without using the Easy helper functions and monadic stateful API:

import Graphics.Rendering.Chart 
import Graphics.Rendering.Chart.Backend.Cairo
import Data.Default.Class
import Control.Lens
import System.Environment(getArgs)

chart = toRenderable layout 
  where
    values = [ ("Mexico City",19.2,e), ("Mumbai",12.9,e), ("Sydney",4.3,e), ("London",8.3,e), ("New York",8.2,e1) ]
    e = 0
    e1 = 25
    pitem (s,v,o) = pitem_value .~ v
                  $ pitem_label .~ s
                  $ pitem_offset .~ o
                  $ def

    layout = pie_title .~ "Relative Populations"
           $ pie_plot . pie_data .~ map pitem values
           $ def

main = renderableToFile def "example5_big.png" chart