prbnmcn-gnuplot

This library provides an relatively basic overlay over Gnuplot. It provides facilities for performing scatterplots, line plots and histograms.

Look no further for the documentation.

Note that some features exposed by the library do not work with Gnuplot versions below 5.4.

Here's a tiny example, plotting a sine function and displaying it on the Qt backend.

let discretize f =
  Array.init 100 (fun i ->
      let x = float_of_int i *. 0.1 in
      Plot.r2 x (f x))

let sin =
  let open Plot in
  Line.line_2d
    ~points:(Data.of_array (discretize sin))
    ~style:
      Style.(default |> set_color Color.red |> set_point ~ptyp:Pointtype.box)
    ~with_points:true
    ~legend:"sin"
    ()

let () =
  let target = Plot.qt () in
  Plot.(run
         ~target
         exec
         (plot2 ~xaxis:"x" ~yaxis:"y" ~title:"sin" [sin]))

This produces something like this.

An alternative to this library is ocaml-gnuplot.