SAC Command Reference Manual

RTREND

SUMMARY

Removes the linear trend.

SYNTAX

[RTR]END  [QUIET|VERBOSE]

INPUT

QUIET:If given, supresses screen output
VERBOSE:If given, there is output to the screen about slope removed, etc.
DEFAULT VALUES:RTR QUIET

DESCRIPTION

A least-squares curve-fit to a straight line is calculated. This straight line (trend and intercept) is then "subtracted" from the data. The data does not have to be evenly spaced. The sequence RMEAN ; RTREND gives the same result as siimply entering RTREND.

OUTPUT: The best-fitting straight line parameters for the last file in the data file list are written to blackboard variables begining with RTR.

  • RTR_SLP is the slope of the line.
  • RTR_SDSLP is the standard deviation in the slope.
  • RTR_YINT is the y intercept of the line.
  • RTR_SDYINT is the standard deviation in the y intercept.
  • RTR_SDDTA is the standard deviation in the data.
  • RTR_CORRCF is the data correlation coeficient.

ERROR MESSAGES

  • 1301: No data files read in.
  • 1307: Illegal operation on spectral file

HEADER CHANGES

DEPMIN, DEPMAX, DEPMEN

LATEST REVISION

July, 2011 (Version 101.5)