Beginner's problem

  • tomih

    tomih - 2009-08-29

    Hi, as an absolute beginner with gnuplot I got stuck with a very basic problem: I'm trying to plot a file with timestamps and two variables. The file is a mysql export and looks like this:

    2009-08 17-21:18:02     1140    0
    2009-08 17-21:19:01     1342    1213
    2009-08 17-21:20:01     1380    2009
    2009-08 17-21:21:01     1560    2511

    I try to plot it as follows:
    set xdata time
    set timefmt "%Y-%m-%d %H-%M-%S"
    plot "testdata" using 1:2 title 'A' with lines, "testdata" using 1:3 title 'B' with lines

    And I get an error:
    Warning: empty x range [3.03858e+08:3.03858e+08], adjusting to [3.00819e+08:3.06897e+08]

    What is wrong and what would be the right way to plot it? I can change the format of the timestamp column, if needed. Thanks already!



    • Edoardo Pasca

      Edoardo Pasca - 2009-08-30

      At least your time format is wrong according to the file excerpt:
      2009-08 17-21:19:01
      set timefmt "%Y-%m-%d %H-%M-%S"

      It should be
      set timefmt "%Y-%m %d-%H:%M:%S"

      but I don't know if it works because of the space.

    • Hans-Bernhard Broeker

      Besides the mismatch between data and timefmt setting, you would have to change your 'using' arguments.  Time data with a blank in it counts as two columns, so your y data are in columns 3 and 4, not 2 and 3.

      • tomih

        tomih - 2009-08-30

        Thanks guys! Such a stupid mistake and such a time that I spent looking for it! I also tried changing the column numbers but that didn't change the situation.

        Stupid me! Thanks!



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