k_means_example.go

package main

import (
	"fmt"
	"github.com/kniren/gota/dataframe"
	"gonum.org/v1/plot"
	"gonum.org/v1/plot/plotter"
	"gonum.org/v1/plot/vg"
	"image/color"
	"log"
	"os"
)

func main() {
	// Open the CSV file.
	advertFile, err := os.Open("fleet_data.csv")
	if err != nil {
		log.Fatal(err)
	}
	defer advertFile.Close()

	// Create a dataframe from the CSV file.
	advertDF := dataframe.ReadCSV(advertFile)

	// Use the Describe method to calculate summary statistics
	// for all of the columns in one shot.
	advertSummary := advertDF.Describe()

	// Output the summary statistics to stdout.
	fmt.Println(advertSummary)

	// Create a histogram for each of the columns in the dataset.
	for _, colName := range advertDF.Names() {

		// Create a plotter.Values value and fill it with the
		// values from the respective column of the dataframe.
		plotVals := make(plotter.Values, advertDF.Nrow())
		for i, floatVal := range advertDF.Col(colName).Float() {
			plotVals[i] = floatVal
		}

		// Make a plot and set its title.
		p, err := plot.New()
		if err != nil {
			log.Fatal(err)
		}
		p.Title.Text = fmt.Sprintf("Histogram of a %s", colName)

		// Create a histogram of our values drawn
		// from the standard normal.
		h, err := plotter.NewHist(plotVals, 16)
		if err != nil {
			log.Fatal(err)
		}

		// Normalize the histogram.
		h.Normalize(1)

		// Add the histogram to the plot.
		p.Add(h)

		// Save the plot to a PNG file.
		if err := p.Save(4*vg.Inch, 4*vg.Inch, colName+"_hist.png"); err != nil {
			log.Fatal(err)
		}
	}

	// Extract the target column.
	yVals := advertDF.Col("Distance_Feature").Float()


	// pts will hold the values for plotting
	pts := make(plotter.XYs, advertDF.Nrow())

	// Fill pts with data.
	for i, floatVal := range advertDF.Col("Speeding_Feature").Float() {
		pts[i].X = floatVal
		pts[i].Y = yVals[i]
	}

	// Create the plot.
	p, err := plot.New()
	if err != nil {
		log.Fatal(err)
	}
	p.X.Label.Text = "Speeding"
	p.Y.Label.Text = "Distance"
	p.Add(plotter.NewGrid())

	s, err := plotter.NewScatter(pts)
	if err != nil {
		log.Fatal(err)
	}
	s.GlyphStyle.Color = color.RGBA{R: 255, B: 128, A: 255}
	s.GlyphStyle.Radius = vg.Points(3)

	// Save the plot to a PNG file.
	p.Add(s)
	if err := p.Save(4*vg.Inch, 4*vg.Inch, "fleet_data_scatter.png"); err != nil {
		log.Fatal(err)
	}

	// Create a scatter plot for each of the features in the dataset.
	for _, colName := range advertDF.Names() {

		// pts will hold the values for plotting
		pts := make(plotter.XYs, advertDF.Nrow())

		// Fill pts with data.
		for i, floatVal := range advertDF.Col(colName).Float() {
			pts[i].X = floatVal
			pts[i].Y = yVals[i]
		}

		// Create the plot.
		p, err := plot.New()
		if err != nil {
			log.Fatal(err)
		}
		p.X.Label.Text = colName
		p.Y.Label.Text = "y"
		p.Add(plotter.NewGrid())

		s, err := plotter.NewScatter(pts)
		if err != nil {
			log.Fatal(err)
		}
		s.GlyphStyle.Radius = vg.Points(3)

		// Save the plot to a PNG file.
		p.Add(s)
		if err := p.Save(4*vg.Inch, 4*vg.Inch, colName+"_scatter.png"); err != nil {
			log.Fatal(err)
		}
	}
}