F# Charting on MacOS (Xamarin)

Question

Hi I'm running on Xamarin 6.1.5 on MacOS I've installed FSharp.Charting 0.90.14

its the first time I'm trying to use it

whether i try to compile or i try in F# interactive, i get this kind of error

(Chart.Line [ for x in 1.0 .. 100.0 -> (x, x ** 2.0) ]).ShowChart();;

System.ArgumentNullException: Value cannot be null.  Parameter name: key   at System.ThrowHelper.ThrowArgumentNullException (...)

EDIT1 I was very stupid indeed and did not install the Gtk version

EDIT2 the above one-liner code in F# interactive "works". It takes some unusual time to execute, but i see the window with the chart. It is not possible to hover on the chart and see coordinates, but maybe its not a default setting ? also, i don't understand how to CLOSE the window where the chart appears. Is everything alright ?

Answer 1

Aren't you trying to use FSharp.Charting package on Mac instead of FSharp.Charting.Gtk, as documentation says you to do?

See https://fslab.org/FSharp.Charting/ReferencingTheLibrary.html

Edit: answering to the edit of the original question: no, there should be no warnings. That's how it works for me:

$ fsharpi

F# Interactive for F# 4.1
Freely distributed under the Apache 2.0 Open Source License

For help type #help;;

> #load "packages/FSharp.Charting.Gtk.0.90.14/FSharp.Charting.Gtk.fsx" ;;
[Loading /Users/avysk/Projects/_Sandbox/testfsharpcharting/packages/FSharp.Charting.Gtk.0.90.14/FSharp.Charting.Gtk.fsx]

namespace FSI_0002.FSharp.Charting
  val verifyMac : unit -> bool
  val isMac : bool
  module FsiAutoShow = begin
  end

> open FSharp.Charting ;;
> (Chart.Line [ for x in 1.0 .. 100.0 -> (x, x ** 2.0) ]).ShowChart();;
Binding session to '/Users/avysk/Projects/_Sandbox/testfsharpcharting/packages/FSharp.Charting.Gtk.0.90.14/lib/net40/OxyPlot.dll'...
Binding session to '/Users/avysk/Projects/_Sandbox/testfsharpcharting/packages/FSharp.Charting.Gtk.0.90.14/lib/net40/OxyPlot.GtkSharp.dll'...
val it : unit = ()

(The window appears immediately.)