stat.m

Univ. of Calgary CREWS的免费地震研究软件

function [trout,tout]=stat(trin,t,dt,flag)
% STAT: static shift a trace
% [trout,tout]=stat(trin,t,dt,flag)
% [trout,tout]=stat(trin,t,dt)
%
% STAT time shifts a time series by dt seconds.
%   A sample at time t on input will be at t+dt on output
%
% trin= tinput trace
% t= time coordinate vector for trin
% dt = static shift in seconds
% flag = 0 ... the time coordinate of trout will equal that of trin
%      = 1 ... the time coordinate of trout will be
%               0<= tout <= max(t)+dt ... dt>0.0
%               -dt <= tout <= max(t) ... dt<0.0
%   ************** default = 0 *************
%
% trout= time shifted output trace
%
% by G.F. Margrave, July, 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

if nargin<4, flag=0; end
% pad trin
 lt= length(trin);
 nt= abs(round(dt/(t(2)-t(1))));
 while length(trin)<lt+nt, trin=padpow2(trin,1); end
 t=xcoord(t(1),t(2)-t(1),trin);
% fft
 [Trin,f]=fftrl(trin,t);
% phase shift
 shiftr=exp(-i*2.*pi*dt*f);
 Trout=Trin.*shiftr;
% inverse fft
 trout=ifftrl(Trout,f);
%
 if flag==0,
  trout=trout(1:lt);
  tout=t;
 else
  if dt>=0,
    trout=trout(1:lt+nt);
    tout=xcoord(0.,t(2)-t(1),trout);
  else
    lt2=length(trout);
    trout=[trout(lt2-nt+1:lt2) trout(1:lt)];
    tout=xcoord((-nt+1)*(t(2)-t(1)),t(2)-t(1),trout);
  end
 end