On 12/12/2020 12:19 PM, Jean-Philippe Rey wrote:
Le 12 déc. 2020 à 11:58, Hans Hagen <j.hagen@xs4all.nl <mailto:j.hagen@xs4all.nl>> a écrit :
On 12/12/2020 10:36 AM, Jean-Philippe Rey wrote:
Dear list,
I am unable to draw a plot using an external file with LMTX. Here is a minimal example
=====================
\usemodule[pgfplots]
\starttext
\starttikzpicture
\startaxis
\addplot table [x=t, y=E] {mfe-addplot.dat};
\stopaxis
\stoptikzpicture
\stoptext
=====================
The ConTeXt run fails with an "Undefined control sequence" error (see attached log file). I don't know if this is an LMTX or PGF issue. The example works fine with MkIV. I tried with the tikz version available on ConTeXt garden (pgf 3.0.1, pgfplots 1.16) and the last one from CTAN (pgf 3.1.7a, pgfplots 1.17) with the same result.
wipe t-tikz.* on your machine in order to use m-tikz.mkiv in the distribution because it looks like it does a bad catcode table change ... that went unnoticed because a chardef'd constant gets typeset (and when that happens before \starttext you won't see it but it actually does introduce some funny char); in lmtx we don't use chardef for that so that can give an error then when loading
anyway, you're not suffering from that i think but better use the right module loader anyway
I wiped t-tikz. The only noticeable difference is that now I need to explicitly \usemodule[tikz] in order to use pgfplots. I checked and found the line
\usemodule[t][tikz]
in t-pgfplots.tex. I guess that explains it.
then you can define the \PackageError macro (I did it with some trial and error but the next seems to work:
\let\PackageError\writestatus
so I'll add something like that to m-tikz.mkiv
As Wolfgang pointed out, \PackageError takes three parameters, the third is meant to be displayed when the user types H to an error prompt. I defined it as
\def/PackageError#1#2#3{\writestatus{#1}{#2 (#3)}}
that effectively displays the error message in the console and the log file.
which still looks bad but at least you don't crash .. i'll look into that later today (as i'm splitting mkiv/lmtx code i use a slightly different file reader so maybe that's it)
I guess that you've pinpointed the problem.
By default, pgfplotstable breaks lines at white space (tab or space according to the pgfplotstable manual). I used tabs as column separators in my demo file. With MKiV, the columns are correctly split but with LMTX, pgfplotstable sees a single column.
I explicitly stated that the columns are separated with tabs:
\addplot table [x=t, y=E, col sep=tab] {mfe-addplot.dat};
and it works. I tried to change the columns separator to a space, instead of a tab and it also works.
I don't know what pgfplotstable uses to split columns, but the conclusion is that with MkIV 'col sep=space' means space or tab, whereas with LMTX it means strictly a space character.
Thank you very much for your help.