gonum · sbinet · Aug 18, 2022 · Aug 17, 2022 · Aug 18, 2022 · Aug 17, 2022
diff --git a/.ci/check-formatting.sh b/.ci/check-formatting.sh
@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -e
+
 test -z "$(goimports -d .)"
 if [[ -n "$(gofmt -s -l .)" ]]; then
 	echo -e '\e[31mCode not gofmt simplified in:\n\n'

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -10,7 +10,7 @@ jobs:
     name: Build
     strategy:
       matrix:
-        go-version: [1.18.x, 1.17.x]
+        go-version: [1.19.x, 1.18.x]
         platform: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.platform }}
     env:
@@ -24,18 +24,18 @@ jobs:
 
     steps:
     - name: Install Go
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v3
       with:
         go-version: ${{ matrix.go-version }}
 
     - name: Checkout code
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3
       with:
         path: ${{ env.GOPATH }}/src/gonum.org/v1/plot
         fetch-depth: 1
 
     - name: Cache-Go
-      uses: actions/cache@v2
+      uses: actions/cache@v3
       with:
         # In order:
         # * Module download cache
@@ -79,7 +79,6 @@ jobs:
       if: matrix.platform == 'ubuntu-latest'
       run: |
         go test -v ./...
-        test -z "$(gofmt -d .)"
         ./.ci/check-imports.sh
         ./.ci/test-coverage.sh
 
@@ -95,4 +94,4 @@ jobs:
 
     - name: Upload-Coverage
       if: matrix.platform == 'ubuntu-latest'
-      uses: codecov/codecov-action@v1
+      uses: codecov/codecov-action@v2
diff --git a/appveyor.yml b/appveyor.yml
@@ -2,7 +2,7 @@ build: off
 
 image: Visual Studio 2019
 
-stack: go 1.17
+stack: go 1.18
 
 clone_folder: c:\gopath\src\gonum.org\v1\plot
 

diff --git a/cmpimg/cmpimg.go b/cmpimg/cmpimg.go
@@ -151,9 +151,9 @@ func cmpImg(v1, v2 image.Image, delta float64) bool {
 // yiqEqApprox compares the colors of 2 pixels, in the NTSC YIQ color space,
 // as described in:
 //
-//   Measuring perceived color difference using YIQ NTSC
-//   transmission color space in mobile applications.
-//   Yuriy Kotsarenko, Fernando Ramos.
+//	Measuring perceived color difference using YIQ NTSC
+//	transmission color space in mobile applications.
+//	Yuriy Kotsarenko, Fernando Ramos.
 //
 // An electronic version is available at:
 //

diff --git a/font/len.go b/font/len.go
@@ -40,10 +40,11 @@ func Points(pt float64) Length {
 // e.g. "42cm" "2.4in" "66pt"
 // If no unit was given, ParseLength assumes it was (postscript) points.
 // Currently valid units are:
-//   mm (millimeter)
-//   cm (centimeter)
-//   in (inch)
-//   pt (point)
+//
+//   - mm (millimeter)
+//   - cm (centimeter)
+//   - in (inch)
+//   - pt (point)
 func ParseLength(value string) (Length, error) {
 	var unit Length = 1
 	switch {

diff --git a/go.mod b/go.mod
@@ -1,6 +1,6 @@
 module gonum.org/v1/plot
 
-go 1.17
+go 1.18
 
 require (
 	gioui.org v0.0.0-20210308172011-57750fc8a0a6
@@ -10,14 +10,15 @@ require (
 	github.com/go-fonts/liberation v0.2.0
 	github.com/go-latex/latex v0.0.0-20210823091927-c0d11ff05a81
 	github.com/go-pdf/fpdf v0.6.0
-	golang.org/x/exp v0.0.0-20191002040644-a1355ae1e2c3
-	golang.org/x/image v0.0.0-20220302094943-723b81ca9867
+	golang.org/x/exp v0.0.0-20220722155223-a9213eeb770e
+	golang.org/x/image v0.0.0-20220722155232-062f8c9fd539
 	gonum.org/v1/gonum v0.11.0
 	rsc.io/pdf v0.1.1
 )
 
 require (
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 // indirect
-	golang.org/x/sys v0.0.0-20210304124612-50617c2ba197 // indirect
+	golang.org/x/exp/shiny v0.0.0-20220722155223-a9213eeb770e // indirect
+	golang.org/x/sys v0.0.0-20211019181941-9d821ace8654 // indirect
 	golang.org/x/text v0.3.7 // indirect
 )
diff --git a/go.sum b/go.sum
@@ -45,8 +45,11 @@ golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529/go.mod h1:yigFU9vqHzYiE8U
 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 v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
-golang.org/x/exp v0.0.0-20191002040644-a1355ae1e2c3 h1:n9HxLrNxWWtEb1cA950nuEEj3QnKbtsCJ6KjcgisNUs=
 golang.org/x/exp v0.0.0-20191002040644-a1355ae1e2c3/go.mod h1:NOZ3BPKG0ec/BKJQgnvsSFpcKLM5xXVWnvZS97DWHgE=
+golang.org/x/exp v0.0.0-20220722155223-a9213eeb770e h1:+WEEuIdZHnUeJJmEUjyYC2gfUMj69yZXw17EnHg/otA=
+golang.org/x/exp v0.0.0-20220722155223-a9213eeb770e/go.mod h1:Kr81I6Kryrl9sr8s2FK3vxD90NdsKWRuOIl2O4CvYbA=
+golang.org/x/exp/shiny v0.0.0-20220722155223-a9213eeb770e h1:pkl1Ko5DrhA4ezwKwdnmO7H1sKmMy9qLuYKRjS7SlmE=
+golang.org/x/exp/shiny v0.0.0-20220722155223-a9213eeb770e/go.mod h1:VjAR7z0ngyATZTELrBSkxOOHhhlnVUxDye4mcjx5h/8=
 golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.0.0-20190910094157-69e4b8554b2a/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
@@ -57,8 +60,8 @@ golang.org/x/image v0.0.0-20201208152932-35266b937fa6/go.mod h1:FeLwcggjj3mMvU+o
 golang.org/x/image v0.0.0-20210607152325-775e3b0c77b9/go.mod h1:023OzeP/+EPmXeapQh35lcL3II3LrY8Ic+EFFKVhULM=
 golang.org/x/image v0.0.0-20210628002857-a66eb6448b8d/go.mod h1:023OzeP/+EPmXeapQh35lcL3II3LrY8Ic+EFFKVhULM=
 golang.org/x/image v0.0.0-20211028202545-6944b10bf410/go.mod h1:023OzeP/+EPmXeapQh35lcL3II3LrY8Ic+EFFKVhULM=
-golang.org/x/image v0.0.0-20220302094943-723b81ca9867 h1:TcHcE0vrmgzNH1v3ppjcMGbhG5+9fMuvOmUYwNEF4q4=
-golang.org/x/image v0.0.0-20220302094943-723b81ca9867/go.mod h1:023OzeP/+EPmXeapQh35lcL3II3LrY8Ic+EFFKVhULM=
+golang.org/x/image v0.0.0-20220722155232-062f8c9fd539 h1:/eM0PCrQI2xd471rI+snWuu251/+/jpBpZqir2mPdnU=
+golang.org/x/image v0.0.0-20220722155232-062f8c9fd539/go.mod h1:doUCurBvlfPMKfmIpRIywoHmhN3VyhnoFDbvIEWF4hY=
 golang.org/x/mobile v0.0.0-20190719004257-d2bd2a29d028/go.mod h1:E/iHnbuqvinMTCcRqshq8CkpyQDoeVncDDYHnLhea+o=
 golang.org/x/mod v0.1.0/go.mod h1:0QHyrYULN0/3qlju5TqG8bIK38QM8yzMo5ekMj3DlcY=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
@@ -72,8 +75,9 @@ golang.org/x/sys v0.0.0-20190312061237-fead79001313/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210304124612-50617c2ba197 h1:7+SpRyhoo46QjKkYInQXpcfxx3TYFEYkn131lwGE9/0=
 golang.org/x/sys v0.0.0-20210304124612-50617c2ba197/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20211019181941-9d821ace8654 h1:id054HUawV2/6IGm2IV8KZQjqtwAOo2CYlOToYqa0d0=
+golang.org/x/sys v0.0.0-20211019181941-9d821ace8654/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=

diff --git a/palette/brewer/brewer.go b/palette/brewer/brewer.go
@@ -15,7 +15,6 @@
 //
 // For more information see:
 // http://www.personal.psu.edu/cab38/ColorBrewer/ColorBrewer_learnMore.html
-//
 package brewer // import "gonum.org/v1/plot/palette/brewer"
 
 import (

diff --git a/plot.go b/plot.go
@@ -494,7 +494,13 @@ func (p *Plot) NominalY(names ...string) {
 //
 // Supported formats are:
 //
-//  eps, jpg|jpeg, pdf, png, svg, tex and tif|tiff.
+//   - .eps
+//   - .jpg|.jpeg
+//   - .pdf
+//   - .png
+//   - .svg
+//   - .tex
+//   - .tif|.tiff
 func (p *Plot) WriterTo(w, h vg.Length, format string) (io.WriterTo, error) {
 	c, err := draw.NewFormattedCanvas(w, h, format)
 	if err != nil {
@@ -509,7 +515,13 @@ func (p *Plot) WriterTo(w, h vg.Length, format string) (io.WriterTo, error) {
 //
 // Supported extensions are:
 //
-//  .eps, .jpg, .jpeg, .pdf, .png, .svg, .tex, .tif and .tiff.
+//   - .eps
+//   - .jpg|.jpeg
+//   - .pdf
+//   - .png
+//   - .svg
+//   - .tex
+//   - .tif|.tiff
 func (p *Plot) Save(w, h vg.Length, file string) (err error) {
 	f, err := os.Create(file)
 	if err != nil {

diff --git a/plotter/boxplot.go b/plotter/boxplot.go
@@ -87,7 +87,7 @@ type BoxPlot struct {
 // NewBoxPlot returns a new BoxPlot that represents
 // the distribution of the given values.  The style of
 // the box plot is that used for Tukey's schematic
-// plots is ``Exploratory Data Analysis.''
+// plots in “Exploratory Data Analysis.”
 //
 // An error is returned if the boxplot is created with
 // no values.

diff --git a/plotter/heat.go b/plotter/heat.go
@@ -145,7 +145,7 @@ func (h *HeatMap) plotRasterized(c draw.Canvas, plt *plot.Plot) {
 	pImg.Plot(c, plt)
 }
 
-//  plotVectorized plots the heatmap using vector-based drawing.
+// plotVectorized plots the heatmap using vector-based drawing.
 func (h *HeatMap) plotVectorized(c draw.Canvas, plt *plot.Plot) {
 	if h.Min > h.Max {
 		panic("contour: invalid Z range: min greater than max")

diff --git a/plotter/johnson.go b/plotter/johnson.go
@@ -125,7 +125,6 @@ func min(a, b int) int {
 // algorithm. The implementation is from the pseudocode at
 //
 // http://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm?oldid=642744644
-//
 type tarjan struct {
 	g graph
 

diff --git a/text/latex.go b/text/latex.go
@@ -50,9 +50,9 @@ func (hdlr Latex) Lines(txt string) []string {
 }
 
 // Box returns the bounding box of the given non-multiline text where:
-//  - width is the horizontal space from the origin.
-//  - height is the vertical space above the baseline.
-//  - depth is the vertical space below the baseline, a positive number.
+//   - width is the horizontal space from the origin.
+//   - height is the vertical space above the baseline.
+//   - depth is the vertical space below the baseline, a positive number.
 func (hdlr Latex) Box(txt string, fnt font.Font) (width, height, depth vg.Length) {
 	cnv := drawtex.New()
 	face := hdlr.Fonts.Lookup(fnt, fnt.Size)

diff --git a/text/plain.go b/text/plain.go
@@ -37,9 +37,9 @@ func (hdlr Plain) Lines(txt string) []string {
 }
 
 // Box returns the bounding box of the given non-multiline text where:
-//  - width is the horizontal space from the origin.
-//  - height is the vertical space above the baseline.
-//  - depth is the vertical space below the baseline, a positive number.
+//   - width is the horizontal space from the origin.
+//   - height is the vertical space above the baseline.
+//   - depth is the vertical space below the baseline, a positive number.
 func (hdlr Plain) Box(txt string, fnt font.Font) (width, height, depth vg.Length) {
 	face := hdlr.Fonts.Lookup(fnt, fnt.Size)
 	ext := face.Extents()

diff --git a/version.go b/version.go
@@ -19,7 +19,9 @@ const root = "gonum.org/v1/plot"
 //
 // If a replace directive exists in the Gonum/plot go.mod, the replace will
 // be reported in the version in the following format:
-//  "version=>[replace-path] [replace-version]"
+//
+//	"version=>[replace-path] [replace-version]"
+//
 // and the replace sum will be returned in place of the original sum.
 //
 // The exact version format returned by Version may change in future.

diff --git a/vg/draw/canvas.go b/vg/draw/canvas.go
@@ -293,11 +293,11 @@ func New(c vg.CanvasSizer) Canvas {
 // image format. Supported formats need to be registered by importing one or
 // more of the following packages:
 //
-//     gonum.org/v1/plot/vg/vgeps // provides eps
-//     gonum.org/v1/plot/vg/vgimg // provides png, jpg|jpeg, tif|tiff
-//     gonum.org/v1/plot/vg/vgpdf // provides pdf
-//     gonum.org/v1/plot/vg/vgsvg // provides svg
-//     gonum.org/v1/plot/vg/vgtex // provides tex
+//   - gonum.org/v1/plot/vg/vgeps: provides eps
+//   - gonum.org/v1/plot/vg/vgimg: provides png, jpg|jpeg, tif|tiff
+//   - gonum.org/v1/plot/vg/vgpdf: provides pdf
+//   - gonum.org/v1/plot/vg/vgsvg: provides svg
+//   - gonum.org/v1/plot/vg/vgtex: provides tex
 func NewFormattedCanvas(w, h vg.Length, format string) (vg.CanvasWriterTo, error) {
 	formats.RLock()
 	defer formats.RUnlock()

diff --git a/vg/len.go b/vg/len.go
@@ -27,10 +27,11 @@ const (
 // e.g. "42cm" "2.4in" "66pt"
 // If no unit was given, ParseLength assumes it was (postscript) points.
 // Currently valid units are:
-//   mm (millimeter)
-//   cm (centimeter)
-//   in (inch)
-//   pt (point)
+//
+//   - mm (millimeter)
+//   - cm (centimeter)
+//   - in (inch)
+//   - pt (point)
 func ParseLength(value string) (Length, error) {
 	return font.ParseLength(value)
 }
diff --git a/vg/vggio/vggio_test.go b/vg/vggio/vggio_test.go
@@ -29,8 +29,8 @@ const deltaGio = 0.05 // empirical value from experimentation.
 // On GitHub Actions and on linux, that headless display may take some time to
 // be properly available and appears to be setup "on demand".
 // So we request it by trying to take a screenshot twice:
-//  - the first time around might fail
-//  - the second time shouldn't.
+//   - the first time around might fail
+//   - the second time shouldn't.
 func init() {
 	if runtime.GOOS != "linux" {
 		return

diff --git a/vg/vgpdf/vgpdf.go b/vg/vgpdf/vgpdf.go
@@ -33,7 +33,7 @@ import (
 // font files, needed by gofpdf to embed fonts in a PDF document.
 // We use cp1252 (code page 1252, Windows Western) to encode characters.
 // See:
-//  - https://en.wikipedia.org/wiki/Windows-1252
+//   - https://en.wikipedia.org/wiki/Windows-1252
 //
 // TODO: provide a Canvas-level func option to embed fonts with a user provided
 // code page schema?

diff --git a/vg/vgsvg/vgsvg.go b/vg/vgsvg/vgsvg.go
@@ -13,7 +13,7 @@
 // this issue.
 //
 // Alternatively, users may want to install the Liberation fonts on their system:
-//  - https://en.wikipedia.org/wiki/Liberation_fonts
+//   - https://en.wikipedia.org/wiki/Liberation_fonts
 package vgsvg // import "gonum.org/v1/plot/vg/vgsvg"
 
 import (
-Original file line number
+Diff line change
@@ Expand Up / @@ -125,7 +125,6 @@ func min(a, b int) int { @@
     // algorithm. The implementation is from the pseudocode at
     //
     // http://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm?oldid=642744644
-    //
     type tarjan struct {
     	g graph
@@ Expand Down @@