Opened 6 years ago
Closed 3 years ago
#13543 closed defect (fixed)
Multicharacter variables not supported in legend_labels
Reported by:  mjo  Owned by:  jason, was 

Priority:  major  Milestone:  sage6.10 
Component:  graphics  Keywords:  
Cc:  kcrisman  Merged in:  
Authors:  Michael Orlitzky  Reviewers:  KarlDieter Crisman 
Report Upstream:  N/A  Work issues:  
Branch:  0fb2fd4 (Commits)  Commit:  0fb2fd4af09b39764464871834b0365bcca6db0b 
Dependencies:  #15870  Stopgaps: 
Description
The simplest example I have is,
sage: hello = var('hello') sage: latex(hello) \mbox{hello} sage: label = '$' + latex(hello) + '$' sage: label $ \mbox{hello} $ sage: plot(x, x, 0, 1, legend_label=label) ERROR: An unexpected error occurred while tokenizing input The following traceback may be corrupted or invalid The error message is: ('EOF in multiline statement', (409, 0)) ... ParseFatalException: Expected end of math '$' $ \mbox{hello} $ (at char 0), (line:1, col:1)
It seems that matplotlib doesn't understand \mbox
. If that's the bug to be fixed, we can simply replace \mbox
with \rm
when passing to matplotlib.
On the other hand, if I've declared hello
to be a symbolic variable, shouldn't it be marked up as a symbolic variable (i.e. left in math mode)?
Change History (22)
comment:1 Changed 6 years ago by
comment:2 Changed 6 years ago by
Ok, that doesn't work on a clean install (you can set an empty $PATH
to convince it to crash). It requires ghostscript, dvipng (see #12276), and full tex installation. For a workaround, you can add,
from matplotlib import rcParams rcParams['text.usetex'] = True
to ~/.sage/init.sage
. The real fix would be one of the following:
 Get Matplotlib to support
\mbox
in their mathtext package.  Replace all occurrences of
\mbox
in Sage with\mathrm
. This might cause regressions.  Ship tex, ghostscript, and dvipng with Sage.
comment:3 Changed 6 years ago by
Please check if #14664 fixes this ticket. If so, we can close this.
comment:4 followup: ↓ 5 Changed 6 years ago by
I don't know, because I can't plot anything thanks to #12276 =)
I'm guessing that it will work if I use typeset='latex'
or typeset='type1'
everywhere, but there are two problems:
 My example in the description will still crash.
 None of this works on a bare sage install, the user has to go find the missing ghostscript, latex, and dvipng dependencies and install them himself.
comment:5 in reply to: ↑ 4 ; followup: ↓ 6 Changed 6 years ago by
Replying to mjo:
I don't know, because I can't plot anything thanks to #12276 =)
I'm guessing that it will work if I use
typeset='latex'
ortypeset='type1'
everywhere, but there are two problems:
 My example in the description will still crash.
Works for me. I have no problems with plotting with typeset='latex'
. And my (external) dvipng is compiled with jpeg. My Sage's gd is not linked to jpeg, but the system gd is.
...5.10.rc0.sagenb/local/lib» ldd libgd.so  grep jpeg ...rc0.sagenb/local/lib [1] » ldd /usr/lib/libgd.so  grep jpeg libjpeg.so.8 => /usr/lib64/libjpeg.so.8 (0x00000030b4200000) ...5.10.rc0.sagenb/local/lib» sage sh Starting subshell with Sage environment variables set. Don't forget to exit when you are done. Beware: * Do not do anything with other copies of Sage on your system. * Do not use this for installing Sage packages using "sage i" or for running "make" at Sage's root directory. These should be done outside the Sage shell. Bypassing shell configuration files... Note: SAGE_ROOT=/home/punarbasu/Installations/sage5.10.rc0.sagenb ...5.10.rc0.sagenb/local/lib» which a dvipng /usr/bin/dvipng ...5.10.rc0.sagenb/local/lib»
 None of this works on a bare sage install, the user has to go find the missing ghostscript, latex, and dvipng dependencies and install them himself.
We can not expect to package latex with Sage. Latex packages are huge! We are better off asking the user to install them externally, especially since they are not an essential component of Sage.
comment:6 in reply to: ↑ 5 Changed 6 years ago by
Replying to ppurka:
Replying to mjo:
I don't know, because I can't plot anything thanks to #12276 =)
I'm guessing that it will work if I use
typeset='latex'
ortypeset='type1'
everywhere, but there are two problems:
 My example in the description will still crash.
Works for me. I have no problems with plotting with
typeset='latex'
. And my (external) dvipng is compiled with jpeg. My Sage's gd is not linked to jpeg, but the system gd is.
Sorry, like I said, I was just guessing. Did you try running dvipng from within the sage shell? This is what I get:
gantu ~ $ dvipng foo.dvi This is dvipng 1.14 Copyright 20022010 JanAke Larsson [1] gantu ~ $ sage sh Starting subshell with Sage environment variables set. Don't forget to exit when you are done. Beware: * Do not do anything with other copies of Sage on your system. * Do not use this for installing Sage packages using "sage i" or for running "make" at Sage's root directory. These should be done outside the Sage shell. Bypassing shell configuration files... Note: SAGE_ROOT=/home/mjo/src/sage5.10.rc2 (sagesh) mjo@gantu:~$ dvipng foo.dvi dvipng: symbol lookup error: dvipng: undefined symbol: gdImageCreateFromJpegPtr (sagesh) mjo@gantu:~$
We can not expect to package latex with Sage. Latex packages are huge! We are better off asking the user to install them externally, especially since they are not an essential component of Sage.
There's a GSOC project that will hopefully go a long ways towards fixing the build system, but if you're going to decide to ship all of sage's dependencies, you've really got to ship all of them. Otherwise certain parts of the program will break, apparently at random.
comment:7 followup: ↓ 8 Changed 6 years ago by
dvipng works from inside sage sh for me.
/tmp/a» ls a.dvi /tmp/a» dvipng a.dvi This is dvipng 1.14 Copyright 20022010 JanAke Larsson [1] /tmp/a» ls a1.png a.dvi /tmp/a» sage sh Starting subshell with Sage environment variables set. Don't forget to exit when you are done. Beware: * Do not do anything with other copies of Sage on your system. * Do not use this for installing Sage packages using "sage i" or for running "make" at Sage's root directory. These should be done outside the Sage shell. Bypassing shell configuration files... Note: SAGE_ROOT=/mnt/usb/Installations/sage5.10.rc0 /tmp/a» rm a1.png /tmp/a» dvipng a.dvi This is dvipng 1.14 Copyright 20022010 JanAke Larsson [1] /tmp/a» ls a1.png a.dvi
comment:8 in reply to: ↑ 7 Changed 6 years ago by
Replying to ppurka:
dvipng works from inside sage sh for me.
Huh. And you use Gentoo, right? So we built dvipng the same way. Beats me.
comment:9 Changed 6 years ago by
Yes. Using pure (i.e. not one of the "forks" like Funtoo, Sabayon, etc) amd64 Gentoo here. :)
Edit: One thing that is different is my shell. I am using zsh.
comment:10 Changed 6 years ago by
 Milestone changed from sage5.11 to sage5.12
comment:11 Changed 5 years ago by
 Milestone changed from sage6.1 to sage6.2
comment:12 Changed 5 years ago by
 Dependencies set to #15870
comment:13 Changed 5 years ago by
Works fine with 6.2.beta6
comment:14 Changed 5 years ago by
Looks like it:
sage: hello = var('hello') sage: latex(hello) \mathit{hello}
The absence of \mbox probably makes a better unit test than the presence of \mathit.
comment:15 Changed 5 years ago by
I think the test for this ticket should be that plotting command works  what exactly is fed into it is not as relevant. Feel free to write the test and I'll review it ;)
comment:16 Changed 5 years ago by
Before the fix, the variable was mathescaped (as well as unplottable). A much lesser bug for sure, but now it's correctly marked up as a variable. I guess we should test that too but checking for \mbox or \mathrm is all I can think of.
comment:17 Changed 5 years ago by
 Milestone changed from sage6.2 to sage6.3
comment:18 Changed 5 years ago by
 Milestone changed from sage6.3 to sage6.4
comment:19 Changed 4 years ago by
 Cc kcrisman added
comment:20 Changed 3 years ago by
 Branch set to u/mjo/ticket/13543
 Commit set to 0fb2fd4af09b39764464871834b0365bcca6db0b
 Status changed from new to needs_review
I guess I shouldn't leave this open forever.
New commits:
0fb2fd4  Trac #13543: Ensure that legends can contain weird variable names.

comment:21 Changed 3 years ago by
 Milestone changed from sage6.4 to sage6.10
 Reviewers set to KarlDieter Crisman
 Status changed from needs_review to positive_review
comment:22 Changed 3 years ago by
 Branch changed from u/mjo/ticket/13543 to 0fb2fd4af09b39764464871834b0365bcca6db0b
 Resolution set to fixed
 Status changed from positive_review to closed
Ok, I finally got a chance to look at this. Matplotlib doesn't use a full TeX implementation by default. It has its own subset called mathtext that it uses unless you tell it to do otherwise via,
This requires you to have "TeX" available in your
$PATH
, whatever that means. I've done some experimenting and it's possible to set this globally via,in
local/lib/python2.7/sitepackages/matplotlib/mpldata/matplotlibrc
.However, I have a full, standalone LaTeX installed everywhere that I work, so I'm not sure if doing this would break a clean install.