Round y values to chart type implemented

cmd/jp/bar.go

@@ -3,14 +3,15 @@ package main
 import (
 	"fmt"
 	"log"
+	"math"
 	"reflect"
 
 	"github.com/sgreben/jp/pkg/data"
 	"github.com/sgreben/jp/pkg/draw"
 	"github.com/sgreben/jp/pkg/plot"
 )
 
-func barPlotData(xv, yv []reflect.Value) (x []string, y []float64) {
+func barPlotData(xv, yv []reflect.Value, digits int) (x []string, y []float64) {
 	for i := range xv {
 		if xv[i].IsValid() && xv[i].CanInterface() {
 			x = append(x, fmt.Sprint(xv[i].Interface()))
@@ -20,15 +21,15 @@ func barPlotData(xv, yv []reflect.Value) (x []string, y []float64) {
 		if yv[i].IsValid() && yv[i].CanInterface() {
 			yvi, ok := yv[i].Interface().(float64)
 			if ok {
-				y = append(y, yvi)
+				y = append(y, math.Round(yvi*math.Pow10(digits))/math.Pow10(digits))
 			}
 		}
 	}
 	return
 }
 
-func barPlot(xv, yv []reflect.Value, c draw.Canvas) string {
-	groups, y := barPlotData(xv, yv)
+func barPlot(xv, yv []reflect.Value, c draw.Canvas, digits int) string {
+	groups, y := barPlotData(xv, yv, digits)
 	chart := plot.NewBarChart(c)
 	data := new(data.Table)
 	if len(y) == 0 {

cmd/jp/main.go

@@ -16,14 +16,15 @@ import (
 )
 
 type configuration struct {
-	Box        draw.Box
-	X          string
-	Y          string
-	XY         string
-	PlotType   enumVar
-	CanvasType enumVar
-	InputType  enumVar
-	HistBins   uint
+	Box         draw.Box
+	X           string
+	Y           string
+	XY          string
+	PlotType    enumVar
+	CanvasType  enumVar
+	InputType   enumVar
+	HistBins    uint
+	RoundDigits int
 }
 
 const (
@@ -97,6 +98,7 @@ func init() {
 	flag.IntVar(&config.Box.Width, "width", 0, "Plot width (default 0 (auto))")
 	flag.IntVar(&config.Box.Height, "height", 0, "Plot height (default 0 (auto))")
 	flag.UintVar(&config.HistBins, "bins", 0, "Number of histogram bins (default 0 (auto))")
+	flag.IntVar(&config.RoundDigits, "round", 6, "Number of digits up to which the y value is to be rounded (applicable to bar type)")
 	flag.Parse()
 	log.SetOutput(os.Stderr)
 	log.SetFlags(log.LstdFlags | log.Lshortfile)
@@ -191,7 +193,7 @@ func main() {
 	case plotTypeScatter:
 		out = scatterPlot(x, y, c)
 	case plotTypeBar:
-		out = barPlot(x, y, c)
+		out = barPlot(x, y, c, config.RoundDigits)
 	case plotTypeHist:
 		out = histogram(x, c, config.HistBins)
 	case plotTypeHist2D:

examples/round.json

@@ -0,0 +1,23 @@
+[
+    {
+        "x": 1,
+        "y": 1.022447
+    },
+    {
+        "x": 2,
+        "y": 2.7639
+    },
+    {
+        "x": 3,
+        "y": 3.4678
+    },
+    {
+        "x": 4,
+        "y": 4.1672
+    },
+    {
+        "x": 5,
+        "y": 5.7396
+    }
+
+]