all: migrate to math/rand/v2

go.mod

@@ -9,7 +9,6 @@ require (
 	codeberg.org/go-pdf/fpdf v0.10.0
 	git.sr.ht/~sbinet/gg v0.6.0
 	github.com/ajstarks/svgo v0.0.0-20211024235047-1546f124cd8b
-	golang.org/x/exp v0.0.0-20241009180824-f66d83c29e7c
 	golang.org/x/image v0.25.0
 	gonum.org/v1/gonum v0.16.0
 	rsc.io/pdf v0.1.1

go.sum

@@ -28,8 +28,6 @@ github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9dec
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/exp v0.0.0-20241009180824-f66d83c29e7c h1:7dEasQXItcW1xKJ2+gg5VOiBnqWrJc+rq0DPKyvvdbY=
-golang.org/x/exp v0.0.0-20241009180824-f66d83c29e7c/go.mod h1:NQtJDoLvd6faHhE7m4T/1IY708gDefGGjR/iUW8yQQ8=
 golang.org/x/image v0.25.0 h1:Y6uW6rH1y5y/LK1J8BPWZtr6yZ7hrsy6hFrXjgsc2fQ=
 golang.org/x/image v0.25.0/go.mod h1:tCAmOEGthTtkalusGp1g3xa2gke8J6c2N565dTyl9Rs=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=

gob/gob_test.go

@@ -8,11 +8,10 @@ import (
 	"bytes"
 	"encoding/gob"
 	"image/color"
+	"math/rand/v2"
 	"os"
 	"testing"
 
-	"golang.org/x/exp/rand"
-
 	"gonum.org/v1/plot"
 	_ "gonum.org/v1/plot/gob"
 	"gonum.org/v1/plot/plotter"
@@ -25,7 +24,7 @@ func init() {
 }
 
 func TestPersistency(t *testing.T) {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	// Get some random points
 	n := 15

palette/moreland/luminance_test.go

@@ -7,10 +7,9 @@ package moreland
 import (
 	"fmt"
 	"image/color"
+	"math/rand/v2"
 	"testing"
 
-	"golang.org/x/exp/rand"
-
 	"gonum.org/v1/gonum/floats/scalar"
 )
 
@@ -151,10 +150,10 @@ func BenchmarkLuminance_At(b *testing.B) {
 			b.Fatal(err)
 		}
 		p.SetMax(1)
-		rand.Seed(1)
+		rng := rand.New(rand.NewPCG(1, 1))
 		b.Run(fmt.Sprintf("%d controls", n), func(b *testing.B) {
 			for i := 0; i < b.N; i++ {
-				if _, err := p.At(rand.Float64()); err != nil {
+				if _, err := p.At(rng.Float64()); err != nil {
 					b.Fatal(err)
 				}
 			}

palette/moreland/smooth_test.go

@@ -7,11 +7,10 @@ package moreland
 import (
 	"image/color"
 	"math"
+	"math/rand/v2"
 	"strings"
 	"testing"
 
-	"golang.org/x/exp/rand"
-
 	"gonum.org/v1/plot/palette"
 )
 
@@ -177,7 +176,6 @@ func testRGB(t *testing.T, i int, label string, c1 color.Color, c2 [3]float64) {
 }
 
 func TestSmoothDiverging_At(t *testing.T) {
-
 	start := msh{M: 80, S: 1.08, H: -1.1}
 	end := msh{M: 80, S: 1.08, H: 0.5}
 	p := newSmoothDiverging(start, end, 88)
@@ -199,9 +197,9 @@ func TestSmoothDiverging_At(t *testing.T) {
 func BenchmarkSmoothDiverging_At(b *testing.B) {
 	p := SmoothBlueRed()
 	p.SetMax(1.0000000001)
-	rand.Seed(1)
+	rng := rand.New(rand.NewPCG(1, 1))
 	for i := 0; i < b.N; i++ {
-		if _, err := p.At(rand.Float64()); err != nil {
+		if _, err := p.At(rng.Float64()); err != nil {
 			b.Fatal(err)
 		}
 	}

plotter/barchart_example_test.go

@@ -7,10 +7,9 @@ package plotter_test
 import (
 	"image/color"
 	"log"
+	"math/rand/v2"
 	"runtime"
 
-	"golang.org/x/exp/rand"
-
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/plotter"
 	"gonum.org/v1/plot/vg"
@@ -158,7 +157,7 @@ func ExampleBarChart() {
 
 // This example shows a bar chart with both positive and negative values.
 func ExampleBarChart_positiveNegative() {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	// Create random data points between -1 and 1.
 	const n = 6

plotter/boxplot_example_test.go

@@ -8,16 +8,15 @@ import (
 	"fmt"
 	"image/color"
 	"log"
-
-	"golang.org/x/exp/rand"
+	"math/rand/v2"
 
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/plotter"
 	"gonum.org/v1/plot/vg"
 )
 
 func ExampleBoxPlot() {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	// Create the sample data.
 	const n = 100

plotter/bubbles_example_test.go

@@ -8,8 +8,7 @@ import (
 	"image/color"
 	"log"
 	"math"
-
-	"golang.org/x/exp/rand"
+	"math/rand/v2"
 
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/plotter"
@@ -21,7 +20,7 @@ import (
 // Each point is plotted with a different radius size depending on
 // external criteria.
 func ExampleScatter_bubbles() {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	// randomTriples returns some random but correlated x, y, z triples
 	randomTriples := func(n int) plotter.XYZs {

plotter/contour_example_test.go

@@ -7,11 +7,10 @@ package plotter_test
 import (
 	"log"
 	"math"
+	"math/rand/v2"
 	"runtime"
 	"testing"
 
-	"golang.org/x/exp/rand"
-
 	"gonum.org/v1/gonum/mat"
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/cmpimg"
@@ -21,7 +20,7 @@ import (
 )
 
 func ExampleContour() {
-	rnd := rand.New(rand.NewSource(1234))
+	rnd := rand.New(rand.NewPCG(1234, 1234))
 
 	const stddev = 2
 	data := make([]float64, 6400)

plotter/contour_test.go

@@ -8,13 +8,12 @@ import (
 	"flag"
 	"fmt"
 	"math"
+	"math/rand/v2"
 	"reflect"
 	"slices"
 	"sort"
 	"testing"
 
-	"golang.org/x/exp/rand"
-
 	"gonum.org/v1/gonum/mat"
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/palette"
@@ -74,7 +73,7 @@ func TestHeatMapWithContour(t *testing.T) {
 }
 
 func TestComplexContours(t *testing.T) {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	if !*visualDebug {
 		return
@@ -121,7 +120,7 @@ func BenchmarkComplexContour32(b *testing.B) { complexContourBench(32, b) }
 var cp map[float64][]vg.Path
 
 func complexContourBench(noise float64, b *testing.B) {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	data := make([]float64, 6400)
 	for i := range data {

plotter/errbars_example_test.go

@@ -6,8 +6,7 @@ package plotter_test
 
 import (
 	"log"
-
-	"golang.org/x/exp/rand"
+	"math/rand/v2"
 
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/plotter"
@@ -16,7 +15,7 @@ import (
 
 // ExampleErrors draws points and error bars.
 func ExampleErrors() {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	randomError := func(n int) plotter.Errors {
 		err := make(plotter.Errors, n)

plotter/filledLine_example_test.go

@@ -7,15 +7,15 @@ package plotter_test
 import (
 	"image/color"
 	"log"
-
-	"golang.org/x/exp/rand"
+	"math/rand/v2"
+	"runtime"
 
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/plotter"
 )
 
 func ExampleLine_filledLine() {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	// randomPoints returns some random x, y points
 	// with some interesting kind of trend.
@@ -46,7 +46,7 @@ func ExampleLine_filledLine() {
 
 	p.Add(filled)
 
-	err = p.Save(200, 200, "testdata/filledLine.png")
+	err = p.Save(200, 200, "testdata/filledLine_"+runtime.GOARCH+".png")
 	if err != nil {
 		log.Panic(err)
 	}

plotter/filledLine_test.go

@@ -7,18 +7,18 @@ package plotter_test
 import (
 	"image/color"
 	"log"
+	"math/rand/v2"
+	"runtime"
 	"testing"
 
-	"golang.org/x/exp/rand"
-
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/cmpimg"
 	"gonum.org/v1/plot/plotter"
 )
 
 // See https://github.com/gonum/plot/issues/488
 func clippedFilledLine() {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	// randomPoints returns some random x, y points
 	// with some interesting kind of trend.
@@ -49,8 +49,8 @@ func clippedFilledLine() {
 
 	p.Add(filled)
 	// testing clipping
-	p.X.Min, p.X.Max = 1, 3
-	p.Y.Max = -1
+	p.X.Min, p.X.Max = 1, 3.5
+	p.Y.Max = 4
 
 	err = p.Save(200, 200, "testdata/clippedFilledLine.png")
 	if err != nil {
@@ -59,6 +59,6 @@ func clippedFilledLine() {
 }
 
 func TestFilledLine(t *testing.T) {
-	cmpimg.CheckPlot(ExampleLine_filledLine, t, "filledLine.png")
+	cmpimg.CheckPlot(ExampleLine_filledLine, t, "filledLine_"+runtime.GOARCH+".png")
 	cmpimg.CheckPlot(clippedFilledLine, t, "clippedFilledLine.png")
 }

plotter/histogram_example_test.go

@@ -8,8 +8,7 @@ import (
 	"image/color"
 	"log"
 	"math"
-
-	"golang.org/x/exp/rand"
+	"math/rand/v2"
 
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/plotter"
@@ -18,7 +17,7 @@ import (
 
 // An example of making a histogram.
 func ExampleHistogram() {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	// stdNorm returns the probability of drawing a
 	// value from a standard normal distribution.

plotter/quartile_example_test.go

@@ -6,16 +6,15 @@ package plotter_test
 
 import (
 	"log"
-
-	"golang.org/x/exp/rand"
+	"math/rand/v2"
 
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/plotter"
 	"gonum.org/v1/plot/vg"
 )
 
 func ExampleQuartPlot() {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	// Create the example data.
 	n := 100

plotter/scatterColor_example_test.go

@@ -8,10 +8,9 @@ import (
 	"fmt"
 	"log"
 	"math"
+	"math/rand/v2"
 	"os"
 
-	"golang.org/x/exp/rand"
-
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/palette/moreland"
 	"gonum.org/v1/plot/plotter"
@@ -24,7 +23,7 @@ import (
 // Each point is plotted with a different color depending on
 // external criteria.
 func ExampleScatter_color() {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	// randomTriples returns some random but correlated x, y, z triples
 	randomTriples := func(n int) plotter.XYZs {
@@ -76,7 +75,8 @@ func ExampleScatter_color() {
 		d := (z - minZ) / (maxZ - minZ)
 		rng := maxZ - minZ
 		k := d*rng + minZ
-		c, err := colors.At(k)
+		// Clamp k to avoid potential overflow due to floating point error.
+		c, err := colors.At(min(k, colors.Max()))
 		if err != nil {
 			log.Panic(err)
 		}

plotter/scatter_example_test.go

@@ -7,8 +7,7 @@ package plotter_test
 import (
 	"image/color"
 	"log"
-
-	"golang.org/x/exp/rand"
+	"math/rand/v2"
 
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/plotter"
@@ -19,7 +18,7 @@ import (
 // ExampleScatter draws some scatter points, a line,
 // and a line with points.
 func ExampleScatter() {
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 
 	// randomPoints returns some random x, y points
 	// with some interesting kind of trend.