Btukfyl

I'm trying to create a plot with pgfplots from CSV file using semicolon as separator and comma as period.

I've tried parsing /pgf/number format/read comma as period as parameter to both axis and addplot.

When used in axis the parameter is ignored and error occurs, indicating need of read comma as period argument.

When used in addplot I receive :

I'm using MixTex 2.9.6888.

My code:

documentclass{article}

usepackage{tikz, pgfplots,siunitx}

usepackage[lotdepth]{subfig}

RequirePackage{filecontents}



begin{filecontents*}{data.csv}

    Column1;MERENI;FI2;URMS2

    ;1;3,006;17,86

    ;2;3,997;20,49

    ;3;5,006;22,86

    ;4;6,009;25,31

    ;5;7,001;27,85

    ;6;8,005;30,52

    ;7;9,014;33,19

    ;8;10,001;35,99

    ;9;11,01;38,73

    ;10;12,005;41,52

end{filecontents*}



begin{document}

begin{figure}

    begin{tikzpicture}

        begin{axis}

            [

            width=linewidth,

            grid=major,

            grid style={dashed,gray!30},

            title={mytitle},

            ylabel=$U_[ef]$,

            xlabel=$f$,

            %/pgf/number format/read comma as period,

            y unit=si{volt},

            x unit=si{hertz},

            ymin = 0, xmin = 0      

            ]

            addplot table[x=FI2, y=URMS2, col sep=semicolon, /pgf/number format/read comma as period] {data.csv};

    end{axis}

    end{tikzpicture}

 end{figure}

 end{document}

After spending (naïvely, I must admit) scrolling the logs looking for "why can't pgfplots read my table", I found out that the problem is not at all related to the format of your data table. Actually, the exact same error shows up if you compile this code:

documentclass{article}

usepackage{pgfplots}

begin{document}

begin{tikzpicture}

  begin{axis}[ylabel=$U_[ef]$]

      addplot coordinates {(0,0)(1,1)};

  end{axis}

end{tikzpicture}

end{document}

This will break because the axis environment takes an optional argument delimited by [...]. When scanning for the ] delimiter TeX will take the first ] that is in the same nesting level (i.e. not inside braces), and the one which fits the requirement is the closing bracket in U_[ef], so the text passed to axis will be ylabel=$U_[ef which will unbalance the $...$ then stuff will break.

To fix this you have to hide the ] in brackets like this:

begin{axis}[ylabel=$U_{[ef]}$]% DO use this

this one

begin{axis}[{{ylabel=$U_[ef]$}}]% Don't use this

and even this one

begin{axis}[ylabel=$U_[ef{]}$]% Don't use this

will compile too, but the output will not be as expected, and the syntax is dubious, at least.

You are also missing the units library to use x unit and y unit. It'll work after that:

documentclass{standalone}

usepackage{tikz,pgfplots,siunitx}

usepgfplotslibrary{units}

RequirePackage{filecontents}

begin{filecontents*}{data.csv}

    Column1;MERENI;FI2;URMS2

    ;1;3,006;17,86

    ;2;3,997;20,49

    ;3;5,006;22,86

    ;4;6,009;25,31

    ;5;7,001;27,85

    ;6;8,005;30,52

    ;7;9,014;33,19

    ;8;10,001;35,99

    ;9;11,01;38,73

    ;10;12,005;41,52

end{filecontents*}

begin{document}

  begin{tikzpicture}

    begin{axis}

      [

        width=linewidth,

        grid=major,

        grid style={dashed,gray!30},

        title={mytitle},

        ylabel=$U_{[ef]}$,

        xlabel=$f$,

        %/pgf/number format/read comma as period,

        y unit=si{volt},

        x unit=si{hertz},

        ymin = 0, xmin = 0

      ]

      addplot table[x=FI2, y=URMS2, col sep=semicolon, /pgf/number format/read comma as period] {data.csv};

    end{axis}

  end{tikzpicture}

end{document}