ismin.m

基于matlab的反演程序,用于地球物理勘探中射线追踪及偏移成像程序.

function [mm,a]=ismin(w);
% ISMIN: test a wavelet (time series) for minimum phase
%
% [mm,a]=ismin(w)
%
% ISMIN factors the z transform of the input and determines if all zeros
% lie outside the unit circle (minimum phase) or not.
%
% w ... wavelet
% mm ... returned as 1 if w is minimum phase, 0 if not
% a ... vector of absolute values of the zeros of w. These
%       must all be greater than 1 for minimum phase.
%
% 
% by G.F. Margrave, May 1991
%
% NOTE: It is illegal for you to use this software for a purpose other
% than non-profit education or research UNLESS you are employed by a CREWES
% Project sponsor. By using this software, you are agreeing to the terms
% detailed in this software's Matlab source file.
 
% BEGIN TERMS OF USE LICENSE
%
% This SOFTWARE is maintained by the CREWES Project at the Department
% of Geology and Geophysics of the University of Calgary, Calgary,
% Alberta, Canada.  The copyright and ownership is jointly held by 
% its author (identified above) and the CREWES Project.  The CREWES 
% project may be contacted via email at:  [e-mail]
% 
% The term 'SOFTWARE' refers to the Matlab source code, translations to
% any other computer language, or object code
%
% Terms of use of this SOFTWARE
%
% 1) Use of this SOFTWARE by any for-profit commercial organization is
%    expressly forbidden unless said organization is a CREWES Project
%    Sponsor.
%
% 2) A CREWES Project sponsor may use this SOFTWARE under the terms of the 
%    CREWES Project Sponsorship agreement.
%
% 3) A student or employee of a non-profit educational institution may 
%    use this SOFTWARE subject to the following terms and conditions:
%    - this SOFTWARE is for teaching or research purposes only.
%    - this SOFTWARE may be distributed to other students or researchers 
%      provided that these license terms are included.
%    - reselling the SOFTWARE, or including it or any portion of it, in any
%      software that will be resold is expressly forbidden.
%    - transfering the SOFTWARE in any form to a commercial firm or any 
%      other for-profit organization is expressly forbidden.
%
% END TERMS OF USE LICENSE

r=roots(flipud(w(:)));
a=abs(r);
ind=find(a<1);
if(isempty(ind))
    mm=1;
else
    mm=0;
end