getcmp.m

这是matlab在地球物理数据处理方面的源码

function [traces,offset]=GetCMP(str,CMPNumber)
%
% Function to get a set of traces and their offset from a 
% file containing a set of CMP (or other) traces that you
% have previously saved using the function putcmp.m
% This would be used to save your cmp gathers if you desire so
% that you do not have to resort the data repeatedly.
% str=string of 7 character ????000
% examples nCMP000  (note the 000 will be converted to the appropriate CMPnumber
% you want to call the gather)
% CMPNumber: integer CMP number
% traces should contain a CMP gather
% offset should contain offsets of the CMP gather
% To run [traces,offset]=GetCMP('stuf000',29)gets a file with the name stuf029.dat
% 
%
nt=1250;
filename=str;
filename(8:11)='.dat';
s=num2str(CMPNumber);
if(CMPNumber<10);
   str(7:7)=s
elseif (CMPNumber<100);
   str(6:7)=s
elseif(CMPNumber<999)
   str(5:7)=s;
else
  'error'
  break
end
fid=fopen(filename,'r','l');
fseek(fid,0,'eof');
n=ftell(fid);
ntraces=n/4/(nt+1);
fseek(fid,0,'bof');
traces=zeros(nt,ntraces);
offset=zeros(1,ntraces);
for i=1:ntraces
  offset(i)=fread(fid,1,'float');
  traces(:,i)=fread(fid,nt,'float');
end  
fclose(fid);
return