1 files changed, 50 insertions, 0 deletions
diff --git a/cmd/jp/hist.go b/cmd/jp/hist.go
new file mode 100644
index 0000000..77c04e6
--- /dev/null
+++ b/cmd/jp/hist.go
@@ -0,0 +1,50 @@
+package main
+
+import (
+	"log"
+	"reflect"
+
+	"github.com/sgreben/jp/pkg/data"
+	"github.com/sgreben/jp/pkg/draw"
+	"github.com/sgreben/jp/pkg/plot"
+)
+
+func histogramData(xv []reflect.Value, nbins uint) (groups []string, counts []float64) {
+	var x []float64
+	for i := range xv {
+		if xv[i].IsValid() && xv[i].CanInterface() {
+			xvi, ok := xv[i].Interface().(float64)
+			if ok {
+				x = append(x, xvi)
+			}
+		}
+	}
+	if len(x) == 0 {
+		log.Fatal("no valid x values given")
+	}
+	bins := data.NewBins(x)
+	bins.Number = int(nbins)
+	if nbins == 0 {
+		bins.ChooseSturges()
+	}
+	hist := data.Histogram(x, bins)
+	groups = make([]string, len(hist))
+	counts = make([]float64, len(hist))
+	for i, b := range hist {
+		groups[i] = b.String()
+		counts[i] = float64(b.Count)
+	}
+	return
+}
+
+func histogram(xv []reflect.Value, c draw.Canvas, nbins uint) string {
+	groups, counts := histogramData(xv, nbins)
+	chart := plot.NewBarChart(c)
+	chart.BarPaddingX = 0
+	data := new(data.Table)
+	for _, g := range groups {
+		data.AddColumn(g)
+	}
+	data.AddRow(counts...)
+	return chart.Draw(data)
+}