Add histogram plots.

examples/fig.ml

@@ -2,17 +2,36 @@
 open Base
 open Matplotlib
 
-let () =
+let left_graph ax =
  let xs = List.init 120 ~f:Float.of_int in
  let ys1 = List.map xs ~f:(fun i -> Float.sin (i /. 20.)) in
  let ys2 = List.map xs ~f:(fun i -> Float.cos (i /. 12.)) in
  let xs = Array.of_list xs in
  let ys1 = Array.of_list ys1 in
  let ys2 = Array.of_list ys2 in
- let _fig, ax = Fig.create_with_ax () in
+ Ax.set_title ax "left ax";
  Ax.set_xlabel ax "x label";
  Ax.set_ylabel ax "sin(x)";
  Ax.grid ax true;
- Ax.plot ax ~color:Red ~xs ys1;
- Ax.plot ax ~color:Green ~linestyle:Dotted ~linewidth:2. ~xs ys2;
+ Ax.plot ax ~label:"sin1" ~color:Red ~xs ys1;
+ Ax.plot ax ~label:"sin2" ~color:Green ~linestyle:Dotted ~linewidth:2. ~xs ys2;
+ Ax.legend ax
+
+let right_graph ax =
+ let rnds =
+ Array.init 5000 ~f:(fun _ ->
+ let u1 = Random.float 1. in
+ let u2 = Random.float 1. in
+ Float.cos (2. *. 3.1415 *. u1) *. Float.sqrt (-. 2. *. Float.log u2))
+ in
+ Ax.hist ax rnds ~bins:50;
+ Ax.set_title ax "hist";
+ Ax.set_xlabel ax "Sample values";
+ Ax.set_ylabel ax "Frequency"
+
+let () =
+ let fig, ax1, ax2 = Fig.create_with_two_axes `horizontal in
+ left_graph ax1;
+ right_graph ax2;
+ Fig.suptitle fig "the figure suptitle";
  Mpl.show ()

src/matplotlib/fig_ax.ml

@@ -40,8 +40,32 @@ module Ax = struct
  in
  ignore (Py.Module.get_function_with_keywords t "grid" [||] keywords)
 
- let plot t ?color ?linewidth ?linestyle ?xs ys =
- Mpl.plot t ?color ?linewidth ?linestyle ?xs ys
+ let legend ?loc t =
+ let keywords =
+ let loc =
+ Option.map loc ~f:(fun loc ->
+ let loc =
+ match loc with
+ | `best -> "best"
+ | `upper_right -> "upper right"
+ | `upper_left -> "upper left"
+ | `lower_left -> "lower left"
+ | `lower_right -> "lower right"
+ | `right -> "right"
+ | `center_left -> "center left"
+ | `center_right -> "center right"
+ | `lower_center -> "lower center"
+ | `upper_center -> "upper center"
+ | `center -> "center"
+ in
+ "loc", Py.String.of_string loc)
+ in
+ List.filter_opt [ loc ]
+ in
+ ignore (Py.Module.get_function_with_keywords t "legend" [||] keywords)
+
+ let plot = Mpl.plot
+ let hist = Mpl.hist
 end
 
 module Fig = struct
@@ -68,6 +92,17 @@ module Fig = struct
  let ax = add_subplot t ~nrows:1 ~ncols:1 ~index:1 in
  t, ax
 
+ let create_with_two_axes ?figsize orientation =
+ let t = create ?figsize () in
+ let nrows, ncols =
+ match orientation with
+ | `horizontal -> 1, 2
+ | `vertical -> 2, 1
+ in
+ let ax1 = add_subplot t ~nrows ~ncols ~index:1 in
+ let ax2 = add_subplot t ~nrows ~ncols ~index:2 in
+ t, ax1, ax2
+
  let suptitle t title =
  ignore (t.&("suptitle")[| Py.String.of_string title |])
 end

src/matplotlib/fig_ax.mli

@@ -5,15 +5,42 @@ module Ax : sig
  val set_xlabel : t -> string -> unit
  val set_ylabel : t -> string -> unit
  val grid : t -> ?which:[`major|`minor|`both] -> ?axis:[`both|`x|`y] -> bool -> unit
+ val legend
+ : ?loc:
+ [`best
+ |`upper_right
+ |`upper_left
+ |`lower_left
+ |`lower_right
+ |`right
+ |`center_left
+ |`center_right
+ |`lower_center
+ |`upper_center
+ |`center]
+ -> t
+ -> unit
 
  val plot
  : t
+ -> ?label:string
  -> ?color:Mpl.Color.t
  -> ?linewidth:float
  -> ?linestyle:Mpl.Linestyle.t
  -> ?xs:float array
  -> float array
  -> unit
+
+ val hist
+ : t
+ -> ?label:string
+ -> ?color:Mpl.Color.t
+ -> ?bins:int
+ -> ?orientation:[ `horizontal | `vertical ]
+ -> ?histtype:[ `bar | `barstacked | `step | `stepfilled ]
+ -> ?xs:float array list
+ -> float array
+ -> unit
 end
 
 module Fig : sig
@@ -30,5 +57,7 @@ module Fig : sig
 
  val create_with_ax : ?figsize:(float * float) -> unit -> t * Ax.t
 
+ val create_with_two_axes : ?figsize:(float * float) -> [`horizontal|`vertical] -> t * Ax.t * Ax.t
+
  val suptitle : t -> string -> unit
 end

src/matplotlib/mpl.ml

@@ -125,12 +125,13 @@ end
 let float_array_to_python xs =
  Py.List.of_array_map Py.Float.of_float xs
 
-let plot p ?color ?linewidth ?linestyle ?xs ys =
+let plot p ?label ?color ?linewidth ?linestyle ?xs ys =
  let keywords =
  List.filter_opt
  [ Option.map color ~f:(fun color -> "color", Color.to_pyobject color)
  ; Option.map linewidth ~f:(fun lw -> "linewidth", Py.Float.of_float lw)
  ; Option.map linestyle ~f:(fun ls -> "linestyle", Linestyle.to_pyobject ls)
+ ; Option.map label ~f:(fun l -> "label", Py.String.of_string l)
  ]
  in
  let args =
@@ -139,3 +140,34 @@ let plot p ?color ?linewidth ?linestyle ?xs ys =
  | None -> [| float_array_to_python ys |]
  in
  ignore (Py.Module.get_function_with_keywords p "plot" args keywords)
+
+let hist p ?label ?color ?bins ?orientation ?histtype ?xs ys =
+ let keywords =
+ List.filter_opt
+ [ Option.map color ~f:(fun color -> "color", Color.to_pyobject color)
+ ; Option.map label ~f:(fun l -> "label", Py.String.of_string l)
+ ; Option.map bins ~f:(fun b -> "bins", Py.Int.of_int b)
+ ; Option.map orientation ~f:(fun o ->
+ let o =
+ match o with
+ | `horizontal -> "horizontal"
+ | `vertical -> "vertical"
+ in
+ "orientation", Py.String.of_string o)
+ ; Option.map histtype ~f:(fun h ->
+ let h =
+ match h with
+ | `bar -> "bar"
+ | `barstacked -> "barstacked"
+ | `step -> "step"
+ | `stepfilled -> "stepfilled"
+ in
+ "histtype", Py.String.of_string h)
+ ]
+ in
+ let args =
+ match xs with
+ | Some xs -> [| List.map (ys::xs) ~f:float_array_to_python |> Py.List.of_list |]
+ | None -> [| float_array_to_python ys |]
+ in
+ ignore (Py.Module.get_function_with_keywords p "hist" args keywords)

src/matplotlib/mpl.mli

@@ -75,9 +75,21 @@ end
 (* Only internal functions below. *)
 val plot
  : Py.Object.t
+ -> ?label:string
  -> ?color:Color.t
  -> ?linewidth:float
  -> ?linestyle:Linestyle.t
  -> ?xs:float array
  -> float array
  -> unit
+
+val hist
+ : Py.Object.t
+ -> ?label:string
+ -> ?color:Color.t
+ -> ?bins:int
+ -> ?orientation:[ `horizontal | `vertical ]
+ -> ?histtype:[ `bar | `barstacked | `step | `stepfilled ]
+ -> ?xs:float array list
+ -> float array
+ -> unit

src/matplotlib/pyplot.ml

@@ -17,6 +17,10 @@ let grid b =
  let p = Mpl.pyplot_module () in
  ignore (p.&("grid")[| Py.Bool.of_bool b |])
 
-let plot ?color ?linewidth ?linestyle ?xs ys =
+let plot ?label ?color ?linewidth ?linestyle ?xs ys =
  let p = Mpl.pyplot_module () in
- Mpl.plot p ?color ?linewidth ?linestyle ?xs ys
+ Mpl.plot p ?label ?color ?linewidth ?linestyle ?xs ys
+
+let hist ?label ?color ?bins ?orientation ?histtype ?xs ys =
+ let p = Mpl.pyplot_module () in
+ Mpl.hist p ?label ?color ?bins ?orientation ?histtype ?xs ys

src/matplotlib/pyplot.mli

@@ -4,9 +4,20 @@ val grid : bool -> unit
 val title : string -> unit
 
 val plot
- : ?color:Mpl.Color.t
+ : ?label:string
+ -> ?color:Mpl.Color.t
  -> ?linewidth:float
  -> ?linestyle:Mpl.Linestyle.t
  -> ?xs:float array
  -> float array
  -> unit
+
+val hist
+ : ?label:string
+ -> ?color:Mpl.Color.t
+ -> ?bins:int
+ -> ?orientation:[ `horizontal | `vertical ]
+ -> ?histtype:[ `bar | `barstacked | `step | `stepfilled ]
+ -> ?xs:float array list
+ -> float array
+ -> unit