SAC Command Reference Manual

PLOTPM

SUMMARY

Generates a "particle-motion" plot of pairs of data files.

SYNTAX

PLOTPM {PRINT {pname} }

INPUT

PRINT {pname}:Print the resultant plot. If a printer name is specified, print to that printer, else use default printer.

DESCRIPTION

In a particle-motion plot one evenly spaced file is plotted against another. For each value of the independent variable, normally time, the value of the dependent variable of the first file is plotted along the y axis and the value of the dependent variable of the second file is plotted along the x axis. For a pair of seismograms this type of plot shows the motion of a "particle" in the plane of the two seismograms as a function of time. A square plot is generated, with the limits along each axis being the minimum and maximum values of the dependent variable. Annotated axes are generated along the bottom and left. Axes labels and title can be set by the XAXIS, YAXIS, and TITLE commands. If no x and y axis labels are set, then the name and azimuth of the station are used as axes labels. The XLIM command can be used to control how much of each file to plot.

EXAMPLES

To create a particle-motion plot of two seismograms, XYZ.T and XYZ.R and set up your own axes labels and title:

SAC> READ XYZ.T XYZ.R
SAC> XLABEL 'Radial component'
SAC> YLABEL 'Transverse component'
SAC> TITLE 'Particle-motion plot for station XYZ'
SAC> PLOTPM

If you wanted to plot only a small part of each file around the first arrival time, you could use the XLIM command:

SAC> XLIM A -0.2 2.0
SAC> PLOTPM

You could also use PLOTPK, possibly in a different graphics window as in this example, to mark which portion of the files you wanted to see in the particle motion plot:

SAC> BEGINWINDOW 2
SAC> PLOTPK
SAC> ... mark the portion you want using X and S
SAC> ... terminate PLOTPK with a Q
SAC> BEGINWINDOW 1
SAC> PLOTPM

LATEST REVISION

May 15, 1987 (Version 10.2)