Is there a way to overlay Haskell GNUPlot plots on top of each other?-CodePudding

I'm using GNUPlot.Simple for Haskell and am trying to plot 2 charts on top of each other. One is using the filled curve format, one is a normal line. The code I am using is :

plotListsStyle []  [ (( defaultStyle {plotType =  FilledCurves} ) , ( zip3 [1,2,3] [2,3,4] [0,1,2] )), ((PlotStyle {plotType = Lines, lineSpec = CustomStyle [PointSize 0.1] }), (zip [1,2,3] [1,2,3]) )]

They work fine when I do them separately as:

plotListsStyle []  [ (( defaultStyle {plotType =  FilledCurves} ) , ( zip3 [1,2,3] [2,3,4] [0,1,2] ))]

and

plotListsStyle [] [((PlotStyle {plotType = Lines, lineSpec = CustomStyle [PointSize 0.1] }), (zip [1,2,3] [1,2,3]) )]

but not when done together. Is it possible to overlay GNUPlots on top of each other?

CodePudding user response：

It looks like you just need to trick the type checker by supplying some extra data that GNUPlot doesn't actually need. Try something like:

import Graphics.Gnuplot.Simple

main = do
  plotListsStyle []
    [ ( defaultStyle {plotType =  FilledCurves}
      , zip3 [1::Double,2,3] [2::Double,3,4] [0::Double,1,2] )
    , ( PlotStyle {plotType = Lines, lineSpec = CustomStyle [PointSize 0.1] }
      , zip3 [1::Double,2,3] [1::Double,2,3] (repeat 0))
--                                           ^^^^^^^^^^
--                            Provide this useless extra data
    ]

The problem here is that plotListsStyle takes a list of tuples, and -- as with all Haskll lists -- all the tuples need to be of the same type, so you can't have data of type [(Double,Double,Double)] in one tuple and data of type [(Double,Double)] in another.