How to use utf-8 in gnuplot?

gregors · 01-10-2023, 10:21 PM

[ This Thread is "semi solved". See last post. ]

Hi there!

I'm using gnuplot to make me some nice diagrams of log files (e.g. containing cpu load/temperature values from "uptime" and "sensors").
Now I would like to use the character "greater-than" ( in HTML > ) in text.

How can I achieve this?

TIA

Gregor

scasey · 01-11-2023, 02:42 AM

You should be able to just type it…you may need to escape it or quote it.
Where do you want to use it? In a label?

pan64 · 01-11-2023, 02:48 AM

yes, you just need to type (or enter) it. Do you have any difficulties?

gregors · 01-11-2023, 10:24 AM

Thanks for your answers!

See https://test.szaktilla.de/plotshot.png

Everything's fine with the degree char, but the "greater or equal" in the headline isn't printed.

Why? How can I fix this?

Gregor

scasey · 01-11-2023, 05:45 PM

Hmmm…that’s not a > Did you try escaping it?
If the chart is going to be rendered on a web page you could try ≥
If > works, you could say “> 5 Stunden” or “>= 6 Stunden”

gregors · 01-11-2023, 06:51 PM

Quote:

Originally Posted by scasey

Hmmm…that’s not a > Did you try escaping it?
If the chart is going to be rendered on a web page you could try ≥
If > works, you could say “> 5 Stunden” or “>= 6 Stunden”

I'm sorry, that was some kind of typo (haven't used HTML actively for about 15 years). I actually mean ≥

Well, yes, I was thinking about working around my problem by first using a plain ">" but now by writing "mind.".

So, I'm still looking for information on how to put an ≥ there - or, generally speaking, on how to put any utf-8 char in an gnuplot label.

Gregor

ljb643 · 01-11-2023, 07:20 PM

Within a double quoted string, you can use UTF-8 escapes like this: \\U+2265
which will produce a greater than or equal to character. The form is \U+HHHH where
HHHH is the hex Unicode value, but the backslash has to be doubled when used
inside double quotes. This is useful if you can't (or don't want to) actually
type the UTF-8 character in your text editor like this: ≥

gregors · 01-11-2023, 09:07 PM

Quote:

Originally Posted by ljb643

Within a double quoted string, you can use UTF-8 escapes like this: \\U+2265
which will produce a greater than or equal to character. The form is \U+HHHH where
HHHH is the hex Unicode value, but the backslash has to be doubled when used
inside double quotes. This is useful if you can't (or don't want to) actually
type the UTF-8 character in your text editor like this: ≥

Unfortunately this doesn't work. So I played around with fonts and characters.
And made another screenshot:
https://test.szaktilla.de/plotshot2.png
As you can see, the Pi character is printed, all others are not.

I'm pretty stumped ...

Gregor

pan64 · 01-12-2023, 01:35 AM

this looks like a locale (language) specific settings (but I can only guess).
Let's say emacs is running with a different locale, and it displays properly everything, but the saved file contains non utf-8 chars.

ljb643 · 01-12-2023, 04:06 PM

Could be a locale problem, but also possibly the font you are using (Bitstream Charter?) simply does not have the characters you want. It looks like it did a few correctly: the degree symbol, and the 'pillcrow' or paragraph symbol. If it does some but not all non-ASCII characters you want, that makes me suspect the font is missing the others. I think you need to find a PostScript font that has a wider Unicode coverage, or change to a different gnuplot driver that uses different fonts.

gregors · 01-12-2023, 04:46 PM

Quote:

Originally Posted by ljb643

Could be a locale problem, but also possibly the font you are using (Bitstream Charter?) simply does not have the characters you want. It looks like it did a few correctly: the degree symbol, and the 'pillcrow' or paragraph symbol. If it does some but not all non-ASCII characters you want, that makes me suspect the font is missing the others. I think you need to find a PostScript font that has a wider Unicode coverage, or change to a different gnuplot driver that uses different fonts.

Meanwhile I suspect that to be some problem outside of gnuplot, too. To make sure it doesn't have anything to do with missing glyphs in the font I changed it to „Liberation Serif“. In Libre Office there's no problem with any „special characters“.

Gregor

PS: Updated shot here: https://test.szaktilla.de/plotshot3.png

gregors · 01-17-2023, 06:46 PM

Hi again,

so since I didn't find out how to print the character I want, I used a work around and played a bit with fonts. Just in case you're interested in the final result, see https://gregor.szaktilla.de/web/plot.pdf

Gregor