使用 gonum.org/v1/plot 画散点图

封装的基础函数

package pchart

import (
	"gonum.org/v1/plot"
	"gonum.org/v1/plot/font"
	"gonum.org/v1/plot/plotter"
	"gonum.org/v1/plot/vg"
	"io/ioutil"
	"log"
	"golang.org/x/image/font/opentype"
)

// 生成散列图
func BuildPlot(title, xlabel, ylabel, filename string, xy plotter.XYer) {

	plotter.DefaultGlyphStyle.Radius = vg.Points(0.5)

	font.DefaultCache.Add([]font.Face{
		{
			Font: font.Font{Typeface: "YaHei"},
			Face: GetZWFont2(),
		},
	})

	plotter.DefaultFont = font.Font{Typeface: "YaHei"}
	plot.DefaultFont = font.Font{Typeface: "YaHei"}

	p := plot.New()

	p.Title.Text = title
	p.X.Label.Text = xlabel
	p.Y.Label.Text = ylabel

	scatter2, _ := plotter.NewScatter(xy)
	p.Add(scatter2)

	// Save the plot to a PNG file.
	if err := p.Save(8*vg.Inch, 8*vg.Inch, filename); err != nil {
		panic(err)
	}
}



const (
	fontFile = "/Library/Fonts/Microsoft-YaHei.ttf" // 需要使用的字体文件
)

func GetZWFont2() *opentype.Font {
	// 读字体数据
	fontBytes, err := ioutil.ReadFile(fontFile)
	if err != nil {
		log.Println(err)
		return nil
	}
	font, err := opentype.Parse(fontBytes)
	if err != nil {
		log.Println(err)
		return nil
	}
	return font
}

绘图

package report

import (
	"fmt"
	"log"
	"sankuai/analysis"
	"sankuai/pchart"
	"sankuai/tools"
	"time"

	"gonum.org/v1/plot/plotter"
)

// 生成 吞吐量和 cpubusy的散点图
func BuildCapacityScatterPlot1(cad *analysis.CacheAppkeyData) string {
	centerTime, err := tools.GetCenterTime(cad.BeginTime, cad.EndTime)
	if err != nil {
		log.Println(err)
	}
	path := pathCheck(centerTime)

	fileName := fmt.Sprintf("%s/csp-%s-%s.png", path, cad.Appkey, centerTime.Format("20060102"))

	pts := plotter.XYs{}
	for curr := cad.BeginTime; !curr.After(cad.EndTime); curr = curr.Add(time.Minute) {

		// 计算吞吐量
		throughput := float64(0.0)
		avg1, ex11 := cad.TransactionAvgMap[curr]
		qpm1, ex12 := cad.TransactionQPMMap[curr]
		avg2, ex21 := cad.TransactionAvgpTestMap[curr]
		qpm2, ex22 := cad.TransactionQPMpTestMap[curr]
		if ex11 && ex12 {
			throughput += avg1 * qpm1
		}
		if ex21 && ex22 {
			throughput += avg2 * qpm2
		}
		// log.Println(throughput)

		// 计算合计 cpubusy
		cpubusy := float64(0.0)
		for _, cmap := range cad.HostsCPUBusyMap {
			cb, ex3 := cmap[curr]
			if ex3 {
				cpubusy += cb
			}
		}

		pts = append(pts, plotter.XY{X: throughput, Y: cpubusy})
	}

	pchart.BuildPlot("容量散点图", "吞吐量", "cpu.busy", fileName, pts)

	return fileName
}

原文地址：http://www.cnblogs.com/ghj1976/p/shi-yong-gonumorgv1plot-hua-san-dian-tu.html