17.4 CATSTAT, statistics of catalogs

This program calculates the yearly, monthly and daily number of events from a given earthquake catalogue and plots the results (written by Mario Villagrán). The input is a standard Nordic file containing only the header lines (compact file). The output is given in three different files with following default file names:

catyear.out :	Output catalogue of the yearly number of events. This file contains two columns of data corresponding to year and the number of events.
catmonth.out :	Output catalogue of the monthly number of events. This file contains three columns of data, corresponding to the year, month and the number of events, respectively.
catday.out :	Output catalogue of the daily number of events. This file contains four columns of data corresponding to the year, month, day and the number of events, respectively.
cathour.out :	Hourly distribution of events within a day interval.

In addition, a series of files with gmt in name give similar output for use with gmtxy (only Unix). The output files can then be used for plotting the histograms for the desired time interval at yearly, monthly or daily intervals. If desired, the corresponding histograms can be plotted interactively on the screen or can be printed. Several other routine programs such as grapher, xyplot, gnuplot or GMT, etc., can also be used for this purpose. The general purpose of this program is to evaluate the catalogue completeness. When run for different magnitude intervals, one can detect the magnitude thresholds above which the catalogue can be considered complete.