charts - Charting with F# does not take in Seq? -


following real-world functional programming blog drawing bar , column charts, trying draw histogram data stored @ set of tuples (data_value, frequency) in lazy sequence.

it not work unless convert sequence list, error message being in case of sequence "the ienumerable 't not support reset function". there way generate histogram/chart etc. using .net library lazily-evaluated sequence?

also (ok newbie query alert), there way make chart persist when program run console? usual system.console.readkey() |> ignore makes chart window hang, , otherwise disappears in instant. i've been using "send interactive" see results til now.

the problem sequences (of type seq<t>, alias ienumerable<t>) generated using f# sequence expression notation not support reset method. method required charting library (because needs obtain data each time redraws screen).

this means that, example, following not work:

seq { x in data -> x } |> fsharpchart.line

many of standard library functions seq module implemented using sequence expressions, result not support reset. can fix converting data list (using list.ofseq) or array (using array.ofseq) or writing code using lists:

[ x in data -> x ] |> fsharpchart.line

... , if you're using function, can take 1 list (not of seq functions available list, need use conversion):

[ x in data -> x ] |> list.choose op |> fsharpchart.line

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