Btukfyl

Assumed we have the following plot from user darthbith to display a pgfplot with a time axis:

Minimum Working Example (MWE):

documentclass{standalone}

usepackage{pgfplots}

usepgfplotslibrary{dateplot, statistics}

pgfplotsset{compat=newest}



usepackage{filecontents}



begin{filecontents*}{data.txt}

    no, date, value

    1, 2015-09-13 21:00:00, 922

    2, 2015-09-13 22:00:00, 3993

    3, 2015-09-13 23:00:00, 3003

    4, 2015-09-14 00:00:00, 991

    5, 2015-09-14 01:00:00, 2021

    6, 2015-09-14 02:00:00, 841

    7, 2015-09-14 03:00:00, 2812

    8, 2015-09-14 14:00:00, 991

    9, 2015-09-14 15:00:00, 231

    10, 2015-09-14 16:00:00, 678

end{filecontents*}



begin{document}



begin{tikzpicture}



begin{axis}[   xlabel=Time,

                ylabel=Value,

                date coordinates in=x,

                table/col sep=comma,

                date ZERO=2015-09-13,

                xticklabel=hour:minute,

                xticklabel style={rotate=90, anchor=near xticklabel},   ]



                addplot+[no markers] table[x=date,y=value] {data.txt};

end{axis}



end{tikzpicture}



end{document}

Screenshot of the result:

Description of the issue:

As you can see, the x-axis has displayed very odd xticks.

How can I force pgfplots to only display even xticks, e.g. nice times like 19:00, 20:00 etc. instead of those unhappy odd random times like 19:12?

I know that I could simply use an approach to only show desired xticks via

• 
  xticks = {20:00, 21:00}
  and


• 
  xtick label = {20:00, 21:00},

however - this is causing a lot of work in case you have longer time spans containing many values. I guess it is possible to force pgfplots to display only even time numbers by itself anyhow?

You only need to adjust the xtick distance (knowing that 1 means 1 day).

documentclass{standalone}

usepackage{pgfplots}

usepgfplotslibrary{dateplot, statistics}

pgfplotsset{compat=newest}



usepackage{filecontents}



begin{filecontents*}{data.txt}

    no, date, value

    1, 2015-09-13 21:00:00, 922

    2, 2015-09-13 22:00:00, 3993

    3, 2015-09-13 23:00:00, 3003

    4, 2015-09-14 00:00:00, 991

    5, 2015-09-14 01:00:00, 2021

    6, 2015-09-14 02:00:00, 841

    7, 2015-09-14 03:00:00, 2812

    8, 2015-09-14 14:00:00, 991

    9, 2015-09-14 15:00:00, 231

    10, 2015-09-14 16:00:00, 678

end{filecontents*}



begin{document}



begin{tikzpicture}



begin{axis}[   xlabel=Time,

                ylabel=Value,

                date coordinates in=x,

                table/col sep=comma,

                date ZERO=2015-09-13 00:00:00,

                xticklabel=hour:minute,

                xtick distance=2/24,

                xticklabel style={rotate=90, anchor=near xticklabel},   ]



                addplot+[no markers] table[x=date,y=value] {data.txt};

end{axis}

end{tikzpicture}

end{document}