How to add percent sign to a label?

[jokaorgua]

Hello. I'm trying to add a text to the plot with the following code

fonts := font.NewCache(liberation.Collection())
plot.DefaultTextHandler = text.Latex{
	Fonts: fonts,
}

labels, err := plotter.NewLabels(plotter.XYLabels{
	XYs: []plotter.XY{
		{X: 0, Y: 0},
	},
	Labels: []string{
		"Money % spent today: 10",
	},
})
if err != nil {
	log.Fatalf("could not create labels: %+v", err)
}

labels.TextStyle[0].Font.Size = 24
labels.TextStyle[0].Color = color.RGBA{B: 255, A: 255}
labels.TextStyle[0].XAlign = draw.XCenter
labels.TextStyle[0].YAlign = draw.YCenter

p.Add(labels)

code was taken from the example https://github.com/gonum/plot/blob/master/text/latex_example_test.go

But I get nothing on the plot except Money. Like % sign cuts everything else.

Could anyone give a hint on how to add a % sign to a string?

[kortschak]

This is a LaTeX issue. % is the LaTeX comment mark. Try \\%.

[jokaorgua]

thanks for the quick response. tried \%, %%, \u0025 - does not work.

maybe there is another way to add a multi-line text box to a plot?

[kortschak]

Did you try \\%?

[jokaorgua]

yes, github escaped :) tried \\% %% \u0025

[kortschak]

I just had a look and it seems the length of the text is the issue. @sbinet will likely have a better understanding of what is going on here.

[kortschak]

With the following change, the plot renders no text. One less, and text is present.

diff --git a/text/latex_example_test.go b/text/latex_example_test.go
index 198086e..b88b4cb 100644
--- a/text/latex_example_test.go
+++ b/text/latex_example_test.go
@@ -47,7 +47,7 @@ func ExampleLatex() {
                Labels: []string{
                        `$\frac{\sqrt{x}}{2\pi\Gamma\gamma}$`,
                        `$LaTeX$`,
-                       "plain",
+                       "plaintext, no",
                        `$\frac{\sqrt{x}}{2\beta}$`,
                },
        })

[sbinet]

I am away from a real keyboard til end of August. I may have a look before that but no guarantees :)

…

-s Aug 16, 2025 13:31:56 Dan Kortschak ***@***.***>:

[Image]*kortschak* left a comment (gonum/plot#803)[#803 (comment)] I just had a look and it seems the length of the text is the issue. @sbinet[https://github.com/sbinet] will likely have a better understanding of what is going on here. — Reply to this email directly, view it on GitHub[#803 (comment)], or unsubscribe[https://github.com/notifications/unsubscribe-auth/AAIFOSHIHKCTADVDLBHNKH33N4JCJAVCNFSM6AAAAACEBKLTW2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTCOJTGYYDKMRRGA]. You are receiving this because you were mentioned.

[sbinet]

apologies for the belated answer.

with the following:

diff --git a/text/latex_example_test.go b/text/latex_example_test.go
index 198086e..b0a02f0 100644
--- a/text/latex_example_test.go
+++ b/text/latex_example_test.go
@@ -46,8 +46,8 @@ func ExampleLatex() {
                },
                Labels: []string{
                        `$\frac{\sqrt{x}}{2\pi\Gamma\gamma}$`,
-                       `$LaTeX$`,
-                       "plain",
+                       `$LaTeX \%$`,
+                       `plain %`,
                        `$\frac{\sqrt{x}}{2\beta}$`,
                },
        })

(ie: use backticks and \% in math-mode.)

I got:

[kortschak]

That explains the percent sign, but the longer text still causes all the text to be lost.

[sbinet]

this is probably unrelated to any LaTeX issue:

diff --git a/text/latex_example_test.go b/text/latex_example_test.go
index 198086e..156fc4c 100644
--- a/text/latex_example_test.go
+++ b/text/latex_example_test.go
@@ -23,14 +23,20 @@ import (
 
 func ExampleLatex() {
        fonts := font.NewCache(liberation.Collection())
-       plot.DefaultTextHandler = text.Latex{
+       plot.DefaultTextHandler = text.Plain{
                Fonts: fonts,
        }
 
        p := plot.New()
-       p.Title.Text = `$f(x) = \sqrt{\alpha x \Gamma}$`
-       p.X.Label.Text = `$\frac{\sqrt{x}}{2\pi\Gamma\gamma}$`
-       p.Y.Label.Text = `$\beta$`
+       p.Title.Text = `title`
+       p.X.Label.Text = `x`
+       p.Y.Label.Text = `y`
 
        p.X.Min = -1
        p.X.Max = +1
@@ -45,10 +51,14 @@ func ExampleLatex() {
                        {X: +0.5, Y: -0.9},
                },
                Labels: []string{
-                       `$\frac{\sqrt{x}}{2\pi\Gamma\gamma}$`,
-                       `$LaTeX$`,
-                       "plain",
-                       `$\frac{\sqrt{x}}{2\beta}$`,
+                       "1",
+                       "2",
+                       "3333333333",
+                       "4",
                },
        })
        if err != nil {

one more 3 and one gets:

I'd say this comes from a too small Y-axis ?
adding a "5" at {X: +0.5, Y: +100} (as the last label), one gets:

if one adds it as the first label, one gets:

to sum up, I suspect there are possibly 2 bugs:

• one in plotter.NewLabels (b/c of the order of the XYLabels matters)
• one around plot.Axis