tex4ht conflict with math in table vs. outside table when using SVG

Question

I found a problem using tex4ht with SVG for math.

I needed to make a table and put math in it. I found that the same math inside the table looks bad compared to the math outside the table. After some debugging, it turned out that tex4ht needs the following configuration to fix the math inside the table

\ifdefined\HCode
\Configure{$}{\PicMath}{\EndPicMath}{}
\Configure{PicMath}{}{}{}{class="math";align="absmiddle"}
\fi

I have no idea why that is. Here is a MWE showing the difference in math inside the table vs. outside when the above tex4ht configuration is missing:

\documentclass[11pt]{article}
\usepackage{amsmath,mathtools,amssymb}   

\begin{document} 

%\ifdefined\HCode
%\Configure{$}{\PicMath}{\EndPicMath}{}
%\Configure{PicMath}{}{}{}{class="math";align="absmiddle"}
%\fi

\begin{align*}
\left( x+y \left( x \right)  \right) {\frac {d}{{d}x}}y \left( x \right) &=x-y \left( x \right)\\
    {t}^{2}+4\,ty \left( t \right) + \left( 2\,{t}^{2}+2\,y \left( t \right)  \right) {\frac {d}{{d}t}}y \left( t \right) &=0\\
    t-2\,{{e}^{ty \left( t \right) }}\sin \left( 2\,t \right) +{{e}^{ty \left( t \right) }}\cos \left( 2\,t \right) y \left( t \right) + \left( -3+{{ e}^{ty \left( t \right) }}t\cos \left( 2\,t \right)  \right) {\frac {d}{{\rm d}t}}y \left( t \right) &=0
\end{align*}

\begin{center}
\begin{tabular}{|c|c|}\hline    
1&$ \left( x+y \left( x \right)  \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) =x-y \left( x \right) $\\\hline 
2&$3\,{t}^{2}+4\,ty \left( t \right) + \left( 2\,{t}^{2}+2\,y \left( t \right)  \right) {\frac {\rm d}{{\rm d}t}}y \left( t \right) =0$\\\hline 
3&$2\,t-2\,{{\rm e}^{ty \left( t \right) }}\sin \left( 2\,t \right) +{{\rm e}^{ty \left( t \right) }}\cos \left( 2\,t \right) y \left( t \right) + \left( -3+{{\rm e}^{ty \left( t \right) }}t\cos \left( 2\,t \right)  \right) {\frac {\rm d}{{\rm d}t}}y \left( t \right) =0$\\\hline
\end{tabular}
\end{center}

\end{document}

Then compiled with

rm -f *.svg
make4ht -ul -f html5+dvisvgm_hashes foo.tex "htm,pic-align,p-width,svg"
make4ht -ul -f html5+dvisvgm_hashes foo.tex "htm,pic-align,p-width,svg"

Clearly the math inside the table cells is not correct. Lots of misalignments over the baseline and the spacing between some of the letters is cramped in a number of places. Below is the result of the same code above, but when removing the comments on the \ifdefined code, so it is now active:

Now the math is correct inside the table. It looks just like the math outside.

Well, you might ask, then why not then keep the \ifdefined code in there and the problem is solved, right?

But here comes the actual problem.

Keeping the \ifdefined code in there to fix the math, causes a big problem somewhere else.

Now tex4ht will no longer accept fixed width column for tables p-width. And I need to have fixed width columns since the actual table will get too wide (it has other columns, not shown here). Making it hard to see the table on the web page without having to scroll all the time.

So now when I want to make a table, and for example have the cells be say 2 inch wide, it will not work.

\documentclass[11pt]{article}
\usepackage{amsmath,mathtools,amssymb}   

\begin{document} 
\ifdefined\HCode
\Configure{$}{\PicMath}{\EndPicMath}{}
\Configure{PicMath}{}{}{}{class="math";align="absmiddle"}
\fi

\begin{center}
\begin{tabular}{|p{1in}|p{2in}|}\hline    
1&$ \left( x+y \left( x \right)  \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) =x-y \left( x \right) $\\\hline 
2&$3\,{t}^{2}+4\,ty \left( t \right) + \left( 2\,{t}^{2}+2\,y \left( t \right)  \right) {\frac {\rm d}{{\rm d}t}}y \left( t \right) =0$\\\hline 
3&$2\,t-2\,{{\rm e}^{ty \left( t \right) }}\sin \left( 2\,t \right) +{{\rm e}^{ty \left( t \right) }}\cos \left( 2\,t \right) y \left( t \right) + \left( -3+{{\rm e}^{ty \left( t \right) }}t\cos \left( 2\,t \right)  \right) {\frac {\rm d}{{\rm d}t}}y \left( t \right) =0$\\\hline
\end{tabular}
\end{center}

\end{document}

Now

rm -f *.svg
make4ht -ul -f html5+dvisvgm_hashes foo.tex "htm,pic-align,p-width,svg"

tex4ht just ignored p-width. To get the width to work, I had to remove the \ifdefined code, like this:

\documentclass[11pt]{article}
\usepackage{amsmath,mathtools,amssymb}   

\begin{document} 

\begin{center}
\begin{tabular}{|p{1in}|p{2in}|}\hline    
1&$ \left( x+y \left( x \right)  \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) =x-y \left( x \right) $\\\hline 
2&$3\,{t}^{2}+4\,ty \left( t \right) + \left( 2\,{t}^{2}+2\,y \left( t \right)  \right) {\frac {\rm d}{{\rm d}t}}y \left( t \right) =0$\\\hline 
3&$2\,t-2\,{{\rm e}^{ty \left( t \right) }}\sin \left( 2\,t \right) +{{\rm e}^{ty \left( t \right) }}\cos \left( 2\,t \right) y \left( t \right) + \left( -3+{{\rm e}^{ty \left( t \right) }}t\cos \left( 2\,t \right)  \right) {\frac {\rm d}{{\rm d}t}}y \left( t \right) =0$\\\hline
\end{tabular}
\end{center}

\end{document}

Now p-width works. But the math became bad again. So back to square one.

I need to be able to have table with fixed width columns, and also have the math look as nice as math outside the table, and still use SVG. But there is a conflict.

For some reason, make4ht math is not rendered correctly inside table cells when using SVG and also using \Configure{$}{\PicMath}{\EndPicMath}{} at same time. May be it is dvisvgm issue. I do not know.

Is there a way around this?

I am using latest TL 2018, with most recent updates for make4ht and tex4ht.

Answer 1

The pic-tabular option requires conversion of all tabular environments to pictures. If you want to convert only some of these tables, it is best to use a custom environment which will convert the enclosed code to pictures.

It can look like this:

% file pictureenv.sty
\newenvironment{pictureenv}{}{}
\endinput

It needs the tex4ht configuration:

% pictureenv.4ht
 \ConfigureEnv{pictureenv}{\Picture*{}}{\EndPicture}{}{}

And usage sample:

\documentclass[11pt]{article}
\usepackage{amsmath,mathtools,amssymb}   

\usepackage{pictureenv}
\begin{document} 


\begin{align*}
\left( x+y \left( x \right)  \right) {\frac {d}{{d}x}}y \left( x \right) &=x-y \left( x \right)\\
    {t}^{2}+4\,ty \left( t \right) + \left( 2\,{t}^{2}+2\,y \left( t \right)  \right) {\frac {d}{{d}t}}y \left( t \right) &=0\\
    t-2\,{{e}^{ty \left( t \right) }}\sin \left( 2\,t \right) +{{e}^{ty \left( t \right) }}\cos \left( 2\,t \right) y \left( t \right) + \left( -3+{{ e}^{ty \left( t \right) }}t\cos \left( 2\,t \right)  \right) {\frac {d}{{\rm d}t}}y \left( t \right) &=0
\end{align*}

\begin{center}
  \begin{pictureenv}
    \begin{tabular}{|p{1in}|p{2in}|}\hline    
    1&$ \left( x+y \left( x \right)  \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) =x-y \left( x \right) $\\\hline 
    2&$3\,{t}^{2}+4\,ty \left( t \right) + \left( 2\,{t}^{2}+2\,y \left( t \right)  \right) {\frac {\rm d}{{\rm d}t}}y \left( t \right) =0$\\\hline 
    3&$2\,t-2\,{{\rm e}^{ty \left( t \right) }}\sin \left( 2\,t \right) +{{\rm e}^{ty \left( t \right) }}\cos \left( 2\,t \right) y \left( t \right) + \left( -3+{{\rm e}^{ty \left( t \right) }}t\cos \left( 2\,t \right)  \right) {\frac {\rm d}{{\rm d}t}}y \left( t \right) =0$\\\hline
  \end{tabular}
  \end{pictureenv}
\end{center}

\end{document}