Matlab-Latex interface

14 Responses

1. 
   Daniel Shub June 7, 2013 at 03:29 Reply

   First, I would like to say that I really like the idea of latexfonts.m, but there is a lot going on in this post, of which I am not sure much is relevant …

   First, LaTeX does not select the font until you add \selectfont. The details are more TeXnical then I understand. If you modify line 35 of latexfonts.m to be

   regular_text = @(fa,sh,se) sprintf('%s%s%s%s %s', family{fa},shape{sh},series{se},'\selectfont',txt);

   so that \selectfont is called, you get a very different result (at least on R2011a Linux) with no warnings and all the fonts showing up.

   The reduction in fonts seems to be limited to removing true type fonts (TTF files) which LaTeX doesn’t use and alternate sizes of the LaTeX fonts. While the the subtle details of the Computer Modern font shape depend on the size, the differences are subtle so losing the alternate sizes is likely not a big deal (especially given all the other problems related to the appearance of MATLAB graphics). Further, TMW has disabled, potentially intentionally, the standard LaTeX size changing commands (e.g., \large gives an error). Changing the font size with set(h, 'fontsize', 20) does change the font size, but it is not clear what the command is doing since it is closed source. It is unlikely to be using LaTeX to do the resizing and rather it is more likely just scaling the text box (and its contents) appropriately.

   Much of the LaTeX processor, much of the source is open, but not free. It starts with tex.m where a tex file is constructed and is processed by a closed source mex file. My guess is this is a somewhat dated tex engine (but since tex is so stable it doesn’t matter). One can modify tex.m to call a local TeX engine (e.g., TeXLive) if the built in one is not sufficient. You can also modify tex.m to include all sorts of packages (although getting the path correct is difficult). Going back to the disabling of font size commands, you can look at tex.m and see MATLAB is using a document class called mwarticle.cls. The only differences between mwarticle.cls and the standard LaTeX article.cls is the disabling of size commands.

2. 
   Ryan W. June 7, 2013 at 07:35 Reply

   This is a problem that I have long been interested in. As stated above, Matlab’s available LaTeX fonts only extend to the Computer Modern font family. As I have rather strict requirements with respect to the fonts that I can use in my scientific figures, this has caused some problems. I looked in to LaPrint, but I want figures that are stand alone and don’t need to be compiled in a LaTeX document. Furthermore, when creating something such as videos in Matlab, you need the actual text in the figure.

   I eventually took the plunge and started sifting through Matlab’s somewhat hacked together distribution of LaTeX. In R2009b, on Mac OS X, I have actually been able to successfully install additional fonts (Helvetica and Symbol), although it is a rather crude implementation. Unfortunately, attempts at a similar implementation in Windows were unsuccessful (although I have come across some posts online that suggest it is possible: https://www.mathworks.com/matlabcentral/newsreader/view_thread/253780 and https://www.mathworks.com/matlabcentral/newsreader/view_thread/283068). This was all fine, as I primarily working in OS X; however, Matlab has been changing the LaTeX engine and my current method no longer works in releases after R2010. I’ve fiddled around with things in an attempt to get the installation procedure to work on the later releases of Matlab; however, they keep moving father and farther from standard LaTeX practices (such as moving from standard naming conventions, having different names between the ttf, pfb, and tfm files, and removing fonts all together as stated above), which makes it difficult to figure out how things work.

   For other peoples reference, here is a basic overview of what LaTeX does when type setting and how Matlab (at least in R2009) works. LaTeX typesetting is a rather complicated procedure. For a good overview of all that you need to install a new LaTeX font, see http://www.tug.org/mactex/fonts/fonttutorial-current.html. Unfortunately, as stated previously, Matlab has been moving away from the structure outlined in the aforementioned website. To start with, there is a font definition file (.fd) file, which outlines which font files are used based on font specifications (such as bold, italic, bold-italic, etc.) and the corresponding encoding. Based on the specified encoding, a enc.def file is read in which specifies the mapping of all of the font symbols. Based on this mapping, the engine takes the text and uses the corresponding tfm files, which contain the font metric information (or sizing), and setups up the location for where each character will be placed (see http://chenfuture.wordpress.com/2009/02/07/tex-fonts-ii-fd-def-and-tfm/ for more information). This is essentially what happens when you call LaTeX from the commandline: latex .tex. In the end, you get a DVI file that contains the location of text based on the tfm information. It is not until you convert the DVI into a post script (using dvips), or a pdf, that the actual font is embedded into the file. Therefore, more often than not, current LaTeX users actually then take this DVI and convert it to a post script file, followed by a conversion to a pdf. However, in the case of Matlab, the DVI information is used natively.

   So, that is how LaTeX works in general when typesetting text. Matlab’s use of the LaTeX engine, to place text in it’s figures, is not at all documented. Everything that I discuss here is based on what I have pieced together myself and is specific to R2009 (although most versions are similarly structured). Lets start with the basic file structure found in Matlab. The base of the installation is found in /Applications/MATLAB_R/sys on a Mac (to find it on Windows, go into the programs folder for Matlab, followed by the “sys” folder). Within this folder, the important folders are
   |-fonts
   |—ttf
   |—–cm
   |—type1
   |—–cm
   |-tex
   |—format
   |—–bigendian
   |—–smallendian
   |—latex
   |—–base
   |—tfm
   The “fonts” folder contains the ttf and type1 font files for Computer Modern (and a couple additional ones such as Euler). The “tex” folder contains the LaTeX specific files. Of interest within this folder are the “tfm” and the “base” folders. The “tfm” folder contains all of the tfm files that correspond to the Computer Modern fonts found in the “fonts” folder. The “tex” folder contains the LaTeX class file “mwarticle.cls” which Matlab uses to typeset the LaTeX text. This class file is essentially LaTeX’s default “article.cls” class, with some modifications made specifically to play nice with Matlab. Finally, the “base” folder contains all of the font definition files (.fd) and the encoding files (.enc).

   There are two ways to go about installing a new font. You can either modify the Matlab file tex.m (which is discussed in a previous post) or you can physically put files into the folder structure. As both methods consist of medling with the Matlab distribution, I strongly suggest backing up files before you start messing around with things. To manually install a new font into the file structure, you essentially need to add the corresponding ttf, type1 (pfb and pfm files), tfm, and fd files into this file structure, along with some modifications to the “mwarticle.cls” file. If you want to install a preexisting LaTeX font, you simply need to track down the ttf, type1, tfm and fd files and place them in their respective folders. Then, to use this font by default, you go into the “mwarticle.cls” file, find the text,
   
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% MODIFIED FOR MATLAB HERE
\renewcommand\normalsize{\fontsize{10pt}{12pt}\selectfont}
\setlength{\textwidth}{6.5in}
\setlength{\textheight}{8in}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


   and add the line:

   \renewcommand{\rmdefault}{<fontname>}

   where <fontname> corresponds to the filename of your .fd file; you could similarly do this for \sfdefault and \ttdefault. You could theoretically specify the font with this command each time you write text in a figure in Matlab using \selectfont, but it is more convenient to do this in the class file if you indent on always using this font (or in the tex.m file). With access to the class file, you can actually customize the fonts quite a bit (for instance, mixing and matching fonts within mathmode, or installing additional LaTeX packages, etc). If you want to install a non-standard font file (i.e., one that doesn’t come with LaTeX), you need to get even more creative and use software, such as FontForge (which is free), and create all of the necessary font files, along with hand writing the .fd file. I have done this for the case of Helvetica and Symbol fonts; however, this is a non-trivial task that I have massaged to work (and only Mac OS X).

   There is a very useful tools to be aware of when trying to install your own fonts into Matlab (although Matlab has recently changed it in R2011 or R2012, making it less helpful). To test to make sure everything is installed correctly, use the following command in the Matlab command line:

   tex('helloworld $x = 5$','verbose',2)

   tex('helloworld $x = 5$','verbose',2)

   which should print out some of the LaTeX compiler information, specifying which font definitions are called and if any errors occurred.

   A final note, it is often not too difficult to get Matlab to show your newly installed font in its figure windows; however, when you go to export these figures to vector formats (such as pdf or eps), it can have issues embedding the correct fonts (especially if you have cooked up your own non-standard font). This is something that I have yet to figure out exactly how things work.

   If anyone has further insight on how LaTeX works in Matlab, especially in the case of newer releases and in the case of Windows, please let me know.

• 
  Dan June 7, 2013 at 15:24 Reply

  If you are having trouble understanding how to deal with the MATLAB LaTeX engine, but understand how to use your local LaTeX engine (e.g., TeXLive or MikTeX), you can cut the MATLAB LaTeX engine out of the loop. For example, you can compile

  \documentclass{article}
\begin{document}
\setbox0=\hbox{$\frac{1}{2}$}\copy0\special{bounds: \the\wd0 \the\ht0 \the\dp0}
\end{document}


  with your local LaTeX engine to create a file called matlab.dvi. You can then overload tex.m to be

  function [dviout,errout,auxout] = tex(varargin) fid = fopen('matlab.dvi'); dviout = fread(fid, 'uint8'); dviout = uint8(dviout); fclose(fid); errout = []; auxout = []; end

  function [dviout,errout,auxout] = tex(varargin) fid = fopen('matlab.dvi'); dviout = fread(fid, 'uint8'); dviout = uint8(dviout); fclose(fid); errout = []; auxout = []; end

  and then call text(0.5, 0.5, 'XXX', 'Interpreter', 'LaTeX') — whatever is in matlab.dvi will show up in your figure. You of course could/should make the overloaded tex.m much more functional and do the compiling based on the input string, but the key is you can completely bypass the MATLAB LaTeX engine. There are still limits as to what can go into a LaTeX hbox and limits on the dvi output format, but standard LaTeX fonts shouldn’t be a problem and my guess is you might be able to get XelaTeX to create an appropriate dvi file with system fonts.

  Right now tex.m is a small undocumented glimpse between a lot of proprietary processing. As long as MATLAB continues to provide this hole by which we can inject user generated dvi content, it doesn’t matter what they do with the LaTeX interpreter.

• 
  Ryan W. June 13, 2013 at 07:27 Reply

  That is a great idea. I’m kind of embarrassed that I didn’t think of this myself (I guess I got caught up with trying to tweak what Matlab already had there). I gave your sample code a try and it worked great (although it might still be a good idea to use Matlab’s mwarticle.cls file, or a variation of it, to get the text located in the proper location in the figure). I briefly gave XeLaTeX a try with hopes that I could use system fonts. As XeLaTeX produces an extended dvi file (xdv), I modified your overload function for tex.m to be

  function[dviout,errout,auxout] = tex(varargin) fid = fopen('matlab.dvi'); dviout = fread(fid, 'uint8'); dviout = uint8(dviout); fclose(fid); errout = []; auxout = []; end

  function[dviout,errout,auxout] = tex(varargin) fid = fopen('matlab.dvi'); dviout = fread(fid, 'uint8'); dviout = uint8(dviout); fclose(fid); errout = []; auxout = []; end

  If I use the same .tex file that you specify above, than everything works the same as with a dvi produced with LaTeX. Unfortunately, when I compile the following code with XeLaTeX:

  \documentclass[11pt]{article}
\usepackage{fontspec}
\setmainfont{Helvetica}

  \begin{document}
\setbox0=\hbox{$x = \alpha$}\copy0\special{bounds: \the\wd0 \the\ht0 \the\dp0}
\end{document}


  in an attempted to use the standard Hevletica font, and feed the xdv file into Matlab, Matlab doesn’t like it and crashes. Any thoughts?

• 
  Jan June 26, 2013 at 05:05 Reply

  I despise the route that matlab has gone into regarding latex since version 2010. Thank you Dan, for the nice work-around. I’m interested to what people have cooked up regadring more elaborate tex.m contraptions.

3. 
   Malcolm Lidierth June 8, 2013 at 04:45 Reply

   Possible alternatives to MATLAB tex interpreting within MATLAB:

   1. Use the MATLAB javacomponent function with JLatexMath which is used in SciLab.

   2. More complex but more flexible if using Java 7 (or 6 with JavaFX added): use javacomponent to add a JFXPanel containing WebView to a MATLAB figure/uipanel and then use MathJax to display the content.

4. 
   Brian June 10, 2013 at 08:28 Reply

   This may be a slight tangent, but I was wondering how to set the background color of a single word in a text box in a figure.
   (aka: highlight with big bold yellow 🙂

   I’ve been using tex to set the font color of individual words successfully,
   but background color doesn’t seem to be supported by Matlab’s tex engine.
   Perhaps overloading matlab’s tex.m is the answer.
   Though I assume I would have to get everyone else who uses my script to install the new LaTeX engine?
   What would be the best LaTeX engine for changing background color?

   My main restriction is that I’m dealing with figures and text objects that already exist, so I can’t simply use a different method (javacomponent) to create the text object.

   Thanks,
   Brian

• 
  Lubos Smolik June 11, 2013 at 06:22 Reply

  The easiest way to highlight some text is to use soul package:

  usepackage{soul} hl{Highlighted text.}

  usepackage{soul} hl{Highlighted text.}

  It is recommended to employ also package color in order to use color references.

  But there is one thing: I’m not sure how MATLAB will interpret \usepackage command. Anyway, you can try it in proper (La)TeX editor and if you find it easy to use then switch to MATLAB and see what happen 😉

• 
  Malcolm Lidierth June 11, 2013 at 07:30 Reply

  Can you not just set the BackgroundColor of the uicontrol?

• 
  Brian June 14, 2013 at 13:44 Reply

  Thanks Lubos. Matlab’s text engine doesn’t seem to support the soul package. When I get some time, I will try to switch out matlab’s tex engine and try the soul package.

  Malcolm, yes, I can (and do) set the background color of the entire uicontrol. But I failed mention earlier that the text box has lots of words in it (sometimes many lines of text). My goal is to highlight only one of the words in yellow…aka showing the results from a text search.

5. 
   Carsten October 16, 2013 at 12:26 Reply

   Hello,

   thanks for this post and the interesting additional information in the comments. However, after some testing and poking around, I don’t believe that tex.m is the relevant point to solve this problem. (For reference: I use R1013a on 64-bit Linux.) True that you can hack tex.m to make Matlab use another (La)TeX engine. But that’s only part of the deal, because the latex run doesn’t really render the font, it only produces the dvi file, which just contains positioning information.

   When I run tex(‘$\sf x = 5$’,’verbose’,2), it reports no errors but a number of successes, including finding cmss10.tfm. That is the file that latex uses in order to typeset cmss10; it contains the font metrics, but not the font glyphs needed for rendering.

   When I put a debugging breakpoint at the end of tex.m, and then run xlabel(‘$\sf x = 5$’, ‘Interpreter’, ‘latex’), I don’t get an error message until the breakpoint, either. At this point, the rendering to the figure window hasn’t happened yet. If I let Matlab continue from the breakpoint, the figure window is updated and the familiar message “Warning: Font cmss10 is not supported” appears.

   The problem does not lie in the built-in latex not being able to process the string into dvi, it lies in Matlab not being able to render the dvi. I suspect that in order to render, Matlab would need a file like mwa_cmss10.ttf in sys/fonts/ttf/cm for screen display and a file like mwa_cmss10.pfb in sys/fonts/type1/cm for eps output.

   A current installation of TeXlive does not contain cmss10 anymore. Computer Modern has been replaced by Latin Modern, available as an OpenType file in texmf/fonts/opentype/public/lm/lmsans10-regular.otf; and I can’t find a pfb version on my system.

   Instead, I tried to copy cmss10.ttf from an installation of matplotlib to sys/fonts/ttf/cm/mwa_cmss10.ttf, but with no effect. I guess there is some kind of font registration in which the file has to be listed to be available. For the pfb-files there is sys/fonts/fonts.scale, fonts.dir, and encodings.dir, but I couldn’t find anything for ttf files.

   I also tried to install cmss10.ttf as a system font. It does show up in Matlab’s font selection dialogue as “cmss10”, but if used the rendering is wrong, and it doesn’t keep ‘Interpreter’ = ‘latex’ from complaining.

   Any more ideas, anyone? I’d really like to be able using latex sans serif again.

• 
  Yair Altman October 16, 2013 at 13:51 Reply

  Have you tried the official route? What does MathWorks tech support have to say about this?

6. How to make fonts available to the LaTeX interpreter in Matlab R2013a? | Technology & Programming Answers November 3, 2013 at 04:32 Reply

   […] Making additional fonts usable therefore consists of two parts: Making it available for the LaTeX interpreter, and making it available for the rendering function. The first part can be tackled by manipulating tex.m, such that it generates the dvi through an independent regular installation of LaTeX, and installing the font to this LaTeX in the usual way (e.g. font packages). See undocumentedmatlab. […]

7. 
   mugurg July 28, 2015 at 02:15 Reply

   If you want to use LaTeX interpreter of MATLAB, create .eps figures, and get the desired font (like Helvetica) instead of Computer Modern fonts, I think I’ve finally found a solution. I actually saw it here: http://stackoverflow.com/questions/11212172/latex-fonts-in-matlab But I needed to scroll down a little bit and read the answers which did not get any upvote.

   Anyways, the trick is to open the resulting .eps file with a text editor and replace cm fonts with Helvetica or whatever you want. For example, change the following lines:

   %%IncludeResource: font mwa_cmr10 /mwa_cmr10 /WindowsLatin1Encoding 120 FMSR

   %%IncludeResource: font mwa_cmr10 /mwa_cmr10 /WindowsLatin1Encoding 120 FMSR

   with the following:

   %%IncludeResource: font Helvetica /Helvetica /WindowsLatin1Encoding 120 FMSR

   %%IncludeResource: font Helvetica /Helvetica /WindowsLatin1Encoding 120 FMSR

   I hope this helps to whomever googles this problem.

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