SUMMARY
Applies a symmetric taper to each end of data.
SYNTAX
TAPER {TYPE HANNING|HAMMING|COSINE},{WIDTH v}
INPUT
TYPE HANNING: Apply a Hanning taper. TYPE HAMMING: Apply a Hamming taper. TYPE COSINE: Apply a cosine taper. WIDTH v: Set the taper width on each end to v. This is a value between 0.0 and 0.5.
DEFAULT VALUES
TAPER TYPE HANNING WIDTH 0.05
DESCRIPTION
A taper is a monotonically varying function between zero and one. It is applied in a symmetric manner to the data such that the signal is zero for the first and last data points and increases smoothly to its original value at an interior point relative to each end.
The COSINE option here is computed using the sin() function as:
DATA(J) = DATA(J) * SIN(OMEGA*J) where OMEGA = PI/(2*N)where N is the length of the taper on each end, and J runs from 1 to N.
The general form for the Hanning or Hamming taper is:
DATA(J)=DATA(J)*(F0-F1*COS(OMEGA*(J))This equation would be applied to the left-hand side of each signal. A symmetric one is applied to the right hand side. The following table defines the various parameters used in the different tapers.
TYPE OMEGA F0 F1 HANNING PI/N 0.50 0.50 HAMMING PI/N 0.54 0.46
ERROR MESSAGES
- 1301: No data files read in.
- 1306: Illegal operation on unevenly spaced file
HEADER CHANGES
DEPMIN, DEPMAX, DEPMEN
LATEST REVISION
January 15, 1985 (Version 9.10)