Add histograms

Author: ruivieira

docs/README.md

@@ -34,3 +34,25 @@ figure2.save("docs/marker.png")
 ```
 
 ![plot](marker.png)
+
+### histograms
+
+With default values:
+
+```nim
+let samples = rnorm(1000, 0.0, 2.0)
+let figure3 = newFigure()
+let hist = newHistogram[float] samples
+figure3.add hist
+```
+
+![plot](hist_default.png)
+
+With custom number of bins:
+
+```nim
+hist.bins = 200
+figure3.save "docs/hist_bins.png"
+```
+
+![plot](hist_bins.png)

docs/examples.nim

@@ -1,4 +1,5 @@
 import "../src/matplotnim"
+import "../../nim-science/science/Distributions"
 
 let x = @[1, 2, 3, 4]
 let y = @[5.5, 7.6, 11.1, 6.5]
@@ -18,4 +19,13 @@ figure2.add sp
 figure2.save("docs/scatterplot_default.png")
 
 sp.marker = "*"
-figure2.save("docs/marker.png")
+figure2.save("docs/marker.png")
+
+let samples = rnorm(1000, 0.0, 2.0)
+let figure3  =newFigure()
+let hist = newHistogram[float] samples
+figure3.add hist
+figure3.save "docs/hist_default.png"
+
+hist.bins = 200
+figure3.save "docs/hist_bins.png"

docs/hist_bins.png

@@ -94,4 +94,22 @@ method render[A,B](this: ScatterPlot[A,B]): string =
 
 proc newScatterPlot*[A,B](x: seq[A], y: seq[B]): ScatterPlot[A, B] =
   ScatterPlot[A, B](colour: "",  x: x, y: y)
-    
+
+# Histogram
+type Histogram[A] = ref object of Plot
+  x*:seq[A]
+  bins*: int
+method render[A](this: Histogram[A]): string =
+  let xs = makeList(this.x)  
+  var options: seq[string] = @[]
+  if this.bins>0:
+    options.add fmt"bins={this.bins}"
+  if len(options)>0:
+    let optstr = options.join(",")
+    return fmt"plt.hist({xs},{optstr})"
+  else:
+    return fmt"plt.hist({xs})"
+
+proc newHistogram*[A](x: seq[A]): Histogram[A] =
+  Histogram[A](bins: 0,  x: x)
+