Thread: spectrograms color-scale and spikes

Started: 2012-06-27 15:33:49
Last activity: 2012-06-27 16:11:59
Topics: SAC Help
marco.olivieri@bo.ingv.it
2012-06-27 15:33:49

Dear All,
I am drawing spectrograms for a set of seismograms and I would like to
use the same color code for amplitudes while, by default,
deep purple is scaled to the max amplitude.
This could also help in case of spikes that saturate the color scale
and little but significant signals disappear.

Any suggestion? I could not find how to set it in the manual.

Thanks in advance.
Marco


  • George Helffrich
    2012-06-27 14:57:20
    Dear Marco -

    Add a point to each spectrogram that is at a specified maximum value. Then the color scale will be uniform. Alternatively, normalize each to the range 0-1 and display each with a scale factor overlaid on the plot.

    On 27 Jun 2012, at 07:33, marco.olivieri<at>bo.ingv.it wrote:


    Dear All,
    I am drawing spectrograms for a set of seismograms and I would like to use the same color code for amplitudes while, by default,
    deep purple is scaled to the max amplitude.
    This could also help in case of spikes that saturate the color scale and little but significant signals disappear.

    Any suggestion? I could not find how to set it in the manual.

    Thanks in advance.
    Marco

    _______________________________________________
    sac-help mailing list
    sac-help<at>iris.washington.edu
    http://www.iris.washington.edu/mailman/listinfo/sac-help



    George Helffrich
    george.helffrich<at>bris.ac.uk



    • Marco Olivieri
      2012-06-27 16:11:59
      thanks George for the suggestion,
      It would work is spikes were not on some data. If the added point is above the potential spike's amplitude, that is more than 10 times the useful signal, all spectrograms will be just blue.
      Marco


      On Jun 27, 2012, at 8:57 AM, George Helffrich wrote:

      Dear Marco -

      Add a point to each spectrogram that is at a specified maximum value. Then the color scale will be uniform. Alternatively, normalize each to the range 0-1 and display each with a scale factor overlaid on the plot.

      On 27 Jun 2012, at 07:33, marco.olivieri<at>bo.ingv.it wrote:


      Dear All,
      I am drawing spectrograms for a set of seismograms and I would like to use the same color code for amplitudes while, by default,
      deep purple is scaled to the max amplitude.
      This could also help in case of spikes that saturate the color scale and little but significant signals disappear.

      Any suggestion? I could not find how to set it in the manual.

      Thanks in advance.
      Marco

      _______________________________________________
      sac-help mailing list
      sac-help<at>iris.washington.edu
      http://www.iris.washington.edu/mailman/listinfo/sac-help



      George Helffrich
      george.helffrich<at>bris.ac.uk




05:46:31 v.ad6b513c