Area chart in LaTeX but with an unknown number of columns

Question

I wanted to draw an area chart like the one seen in this question, but I want to use a file like this one, where the number of columns is unknown:

Generation,Dog,Cat
0,100,4800
1,200,4700
2,100,4400
3,100,3800
4,100,2800

The file could also look like this:

Generation,Dog,Cat,Elefant
0,100,4800,100
1,200,4700,100
2,100,4400,400
3,100,3800,1100
4,100,2800,2100

How would I go about doing that?

I am also kind of new to LaTeX, so feel free to edit my question and tags.

score 1 · Accepted Answer · answered Dec 28 '20 at 21:10

The detail implementation is a matter of taste, but key to do so is

to find out the number of columns given in the data file with \pgfplotstablegetcolsof,
store it in a variable with \pgfmathtruncatemacro and
then loop through the file using one of the "foreach" commands, e.g. \pgfplotsinvokeforeach.

Because you didn't provide a full MWE yourself I used Zarko's answer as basis and modified it with the approach I already showed in this answer.

Something similar you can also find in the following answers

Hope that is sufficient for you for a good start.

% used PGFPlots v1.17
\begin{filecontents*}{data.csv}
date,backlog,wip,finished
2015-01-06,54,27,3
2015-01-13,55,27,5
2015-01-20,55,27,5
2015-01-27,54,27,8
2015-02-03,54,27,8
2015-02-10,56,27,10
2015-02-17,56,25,12
2015-02-24,63,24,17
2015-03-02,63,21,17
2015-03-09,59,23,20
2015-03-16,59,25,21
2015-03-23,55,27,26
2015-03-30,55,30,26
2015-04-06,62,28,30
2015-04-13,62,28,30
2015-04-20,65,22,40
2015-04-27,65,22,40
2015-05-04,61,22,44
2015-05-11,61,20,47
2015-05-18,60,21,50
2015-05-25,59,21,50
\end{filecontents*}
\documentclass[border=5pt]{standalone}
\usepackage{pgfplots}
    \usepgfplotslibrary{dateplot}
    \pgfplotsset{compat=1.17}
    % ----------------------------------------------------------------------
    \newcommand{\plotfile}[1]{
        \pgfplotstableread[col sep=comma]{#1}{\table}
        \pgfplotstablegetcolsof{\table}
        \pgfmathtruncatemacro\numberofcols{\pgfplotsretval-1}
        \pgfplotsinvokeforeach{1,...,\numberofcols}{
            \pgfplotstablegetcolumnnamebyindex{##1}\of{\table}\to{\colname}
            \addplot table [y index=##1] {\table}
                \closedcycle;
            \addlegendentryexpanded{\colname}
        }
    }
    % ----------------------------------------------------------------------
\begin{document}
\begin{tikzpicture}
    \begin{axis}[
        date coordinates in=x,
        xticklabel={\day.\month.\year},
        xticklabel style={
            rotate=90,
            anchor=near xticklabel,
        },
        xmin={2015-01-06},
        xmax={2015-05-25},
        ymin=0,
        ymax=140,
        max space between ticks=20,
        stack plots=y,
        area style,
    ]
        \plotfile{data.csv}
    \end{axis}
\end{tikzpicture}
\end{document}

First of all: Thank you! But how can I have the first column as an index though? — weisbrja, Dec 29 '20 at 17:18
You are welcome. To your question; there are two ways: 1. The best way is to (simply) change the data in the file. 2. Add x expr=\coordindex, before y index. — Stefan Pinnow, Dec 29 '20 at 18:35
When I insert x expr=\coordindex, before y index, I get an error.
Also... This is answer works with dates, but how do I use it with regular integers? — weisbrja, Dec 29 '20 at 19:01
Of course you need to remove all the stuff related to "dates", i.e. the first three axis options. — Stefan Pinnow, Dec 29 '20 at 19:06
Hmm, the best way to learn PGFPlots is to "scroll" through the manual. And there you could also have a look what the two things do. Here in short: x expr lets you state an expression. And here the expression simply is \coordindex which gives the coordinate index, i.e. the row number (without the header and starting from 0). — Stefan Pinnow, Dec 29 '20 at 20:24

Area chart in LaTeX but with an unknown number of columns

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