OCTAVE yulewalker.m - Compute Yule-Walker all pole spectrum
yulewalker prompts for:
BSEGY file name
(*.seg) (shell terminal input)
Define input type, data or autocorrelation (GUI entry box)
GUI pop up showing max time and sample interval, click OK
Trace number to select in file (GUI entry box, default max
available)
Max Time to include (only if data) (GUI entry box, default
max available)
Maximum frequency for plots (GUI entry box, default 200 Hz)
GUI pop up Remove DC ? (only if data) (Click Yes or No,
Shows DC present)
Pick Maximum Lag, Autocorrelation (mouse click on waveform,
sets order of process)
Basic Seismic
Utilities (BSU) program run in Octave or Matlab. Within an
octave session, type yulewalker and then on prompt,
enter the bsegy format file name (example: 1001.seg). Dialog
prompts as shown above. If input is autocorrelation computed
from program bxcr, it will be a two sided
autocorrelation. This 2 sided auto will be displayed as 1
sided half for mouse click which sets the number of samples
of the 1 sided auto to include, and that sets the order of
the process.
Other programs like traplt use FFT to compute spectrum. This
program differs in that one selects the order of the process
by clicking with the mouse on the maxumum number of samples
to include in the autocorrelation. Code employs levinson()
and polyval() algorithms.
Figure 1 time
domain plot of selected signal (if data) or alternatively
the 2 sided auto.
Figure 2 Autocorrelation plot (computed if data input)
Figure 3 All Pole amplitude spectrum, linear scale
Figure 4 All Pole amplitude spectrum, decibel (log scale)
File: ywplot.ps Postscript Plot linear scale
File: plotspec.gp Gnuplot version that generates both
X-window and Postscript plots
File: yw.dat text file with 3 columns: frequency, amplitude,
decibels
segyinfo.m
bsegin.m
traplt(1) bxcr(1) OCTAVE: segyinfo.m(7) bsegin.m(7) traplt.m(7)
No known bugs.
Copyright © 2017 by Paul Michaels
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
P. Michaels, PE. <pm@cgiss.boisestate.edu>