SUMMARY

Subtracts a set of data files from data in memory.

SYNTAX

SUBF {NEWHDR ON|OFF} filelist

INPUT

NEWHDR ON|OFF:	By default, the resultant file will take its header field from the original file in memory. Turning NEWHDR ON, causes the header fields to be taken from the new file in the filelist.
filelist:	A list of SAC binary data files. This list may contain simple filenames, full or relative pathnames, and wildcard characters. See the READ command for a complete description.

DESCRIPTION

This command can be used to subtract a single file from a set of files or to subtract one set of files from another set. An example of each case is presented below. The files must be evenly spaced and should have the same sampling interval and number of points. This last two restrictions can be eliminated using the BINOPERR command. If there are more data files in memory than in the filelist, then the last file in the filelist is used for the remainder of the data files in memory.

EXAMPLES

To subtract one file from three other files:

SAC> READ FILE1 FILE2 FILE3
SAC> SUBF FILE4

To subtract two files from two other files:

SAC> READ FILE1 FILE2
SAC> SUBF FILE3 FILE4

HEADER CHANGES

If NEWHDR is OFF (the default) the headers in memory are unchanged). If NEWHDR is ON, the headers are replaced with the headers from the files in the filelist.

DEPMIN, DEPMAX, DEPMEN

ERROR MESSAGES

• 1301: No data files read in.
• 1803: No binary data files read in.
• 1307: Illegal operation on spectral file
• 1306: Illegal operation on unevenly spaced file
• 1801: Header field mismatch:
  • either the sampling interval or the number of points are not equal. - can be controlled using the BINOPERR command.

WARNING MESSAGES

• 1802: Time overlap:
  • the file subtraction is still performed.

SEE COMMANDS

READ, BINOPERR

LATEST REVISION

May 26, 1999 (Version 0.58)