SYNOPSIS
PERL PROGRAM NAME:
AUTHOR: Juan Lorenzo (Perl module only)
DATE:
DESCRIPTION:
Version:
USE
NOTES
Examples
SYNOPSIS
SEISMIC UNIX NOTES SUDGWAVEFORM - make Gaussian derivative waveform in SU format
sudgwaveform >stdout [optional parameters]
Optional parameters:
n=2 order of derivative (n>=1)
fpeak=35 peak frequency
nfpeak=n*n max. frequency = nfpeak * fpeak
nt=128 length of waveform
shift=0 additional time shift in s (used for plotting)
sign=1 use =-1 to change sign
verbose=0 =0 don't display diagnostic messages
=1 display diagnostic messages
Notes:
This code computes a waveform that is the n-th order derivative of a
Gaussian. The variance of the Gaussian is specified through its peak
frequency, i.e. the frequency at which the amplitude spectrum of the
Gaussian has a maximum. nfpeak is used to compute maximum frequency,
which in turn is used to compute the sampling interval. Increasing
nfpeak gives smoother plots. In order to have a (pseudo-) causal
pulse, the program computes a time shift equal to sqrt(n)/fpeak. An
additional shift can be applied with the parameter shift. A positive
value shifts the waveform to the right.
Examples:
2-loop Ricker: dgwaveform n=1 >ricker2.su
3-loop Ricker: dgwaveform n=2 >ricker3.su
Sonic transducer pulse: dgwaveform n=10 fpeak=300 >sonic.su
To display use suxgraph. For example:
dgwaveform n=10 fpeak=300 | suxgraph style=normal &
For other seismic waveforms, please use "suwaveform".
Credits:
Werner M. Heigl, February 2007
This copyright covers parts that are not part of the original
CWP/SU: Seismic Un*x codes called by this program:
Copyright (c) 2007 by the Society of Exploration Geophysicists.
For more information, go to http://software.seg.org/2007/0004 .
You must read and accept usage terms at:
http://software.seg.org/disclaimer.txt before use.
Revision history:
Original SEG version by Werner M. Heigl, Apache E&P Technology,
February 2007.
Jan 2010 - subroutines deriv_n_gauss and hermite_n_polynomial moved
to libcwp.a/
User's notes (Juan Lorenzo) untested
CHANGES and their DATES
Import packages
instantiation of packages
Encapsulated hash of private variables
sub Step
collects switches and assembles bash instructions by adding the program name
sub note
collects switches and assembles bash instructions by adding the program name
sub clear
sub fpeak
sub n
sub nfpeak
sub nt
sub shift
sub sign
sub verbose
sub get_max_index
max index = number of input variables -1