Make sure latex doesn't do weird things with R output

[kcrisman]

jsmath doesn't understand output from R, so you have to turn off typesetting for it to work. E.g., it doesn't know what to do with this table which results from R output - I guess it's really a latex() problem.

sage: r.data('Cars93')
[1] "sage0"
sage: a._latex_()

% latex.default(sage3, file = "") 
%
\begin{table}[!tbp]
 \begin{center}
 \begin{tabular}{l}\hline\hline
\multicolumn{1}{c}{}\tabularnewline
\hline
sage0\tabularnewline
\hline
\end{tabular}

\end{center}

\end{table}

[jason]

Can R latex its own expressions?

If not, we might explore the rpy2 interface a bit more to get the data into python formats.

Also, when evaluating in the R system, we ought to enclose things in a div that tells jsmath "Hands off!"

[kcrisman]

Replying to jason:

Can R latex its own expressions?

Apparently using the Hmisc package. From our own doctests in r.py:

    def _latex_(self):
        r"""
        Return LaTeX representation of this R object.

        This calls the \code{latex} command in R.

        OUTPUT:
           a latex expression (basically a string)
        
        EXAMPLES:
            sage: latex(r(2))  #optional requires the Hmisc R package
            2
        """
        self._check_valid()
        P = self.parent()
        # latex is in Hmisc, this is currently not part of Sage's R!!!
        try:
            P.library('Hmisc')
        except ImportError:
            raise RuntimeError, "The R package 'Hmisc' is required for R to LaTeX conversion, but it is not available."
        return LatexExpr(P.eval('latex(%s, file="");'%self.name()))

Note that this requires the package 'survival', which is also recommended but not currently in Sage.

Anyway, I checked some more and apparently the problem is that jsmath doesn't understand the latex output created by Hmisc - namely, it doesn't know what a table is, nor center, nor tabular.

So maybe if EMBEDDED_MODE=True, we should have a thing that strips out all that other stuff and just puts in the stuff in the middle. Incidentally, the output in the optional doctest above is incorrect, we get

% latex.default(sage0, file = "") 
%
\begin{table}[!tbp]
 \begin{center}
 \begin{tabular}{r}\hline\hline
\multicolumn{1}{c}{}\tabularnewline
\hline
$2$\tabularnewline
\hline
\end{tabular}

\end{center}

\end{table}

so maybe this was with a previous version of Hmisc.

Or we could even strip out those things and replace them with equivalent HTML stuff when EMBEDDED_MODE is true.

[iandrus]

FWIW, this affects sage-mode in Emacs when typesetting output as well.