readshadebin.m

水声模型 很不错的东西

function [ title, freq, nsd, nrd, nrr, sd, rd, rr, tlt, FileStatus ] = ReadShadeBin( filename )

% Reads in TL surfaces from a binary Bellhop/Kraken .SHD file 
% without having to convert to ASCII first.
% Chris Tiemann, Feb. 2001
% Modified by Alec Duncan, June 2002 to add error checking

FileStatus = 1;
fid = fopen( filename, 'rb' );
if fid < 0
   uiwait(warndlg(['Couldn''t open input file: ' filename]));

   FileStatus = 0;
   title = '';
   freq = [];
   nsd = [];
   nrd = [];
   nrr = [];
   sd = [];
   rd = [];
   rr = [];
   tlt = [];
   return;
end

   
recl = fread( fid, 1, 'int32'); %record length in bytes will be 4*recl
title = setstr( fread( fid, 80, 'uchar' ) )';  

fseek(fid, 4*recl, -1); %reposition to end of first record
plottype = fread(fid, 10, 'uchar');
xs    = fread( fid, 1, 'float32');
ys    = fread( fid, 1, 'float32');
theta = fread( fid, 1, 'float32');

fseek(fid, 2*4*recl, -1); %reposition to end of second record
freq = fread( fid, 1, 'float32'); 
nsd  = fread( fid, 1, 'int32');
nrd  = fread( fid, 1, 'int32');
nrr  = fread( fid, 1, 'int32');

if (nrr<= 0) | (nsd <= 0) | (nrd <= 0) | (freq <= 0)
   FileStatus = 0;
   fclose(fid);
   Msg = {'Invalid shade file parameters:', ...
            ['Frequency = ' num2str(freq)], ...
            ['Number of source depths = ' int2str(nsd)], ...
            ['Number of receiver depths = ' int2str(nrd)], ...
            ['Number of receiver ranges = ' int2str(nrr)]};
      
   uiwait(warndlg(Msg));
   sd = [];
   rd = [];
   rr = [];
   tlt = [];

   return;
end

fseek(fid, 3*4*recl, -1); %reposition to end of third record
sd = fread( fid, nsd, 'float32');

fseek(fid, 4*4*recl, -1); %reposition to end of fourth record
rd = fread( fid, nrd, 'float32');

fseek(fid, 5*4*recl, -1); %reposition to end of fifth record
rr = fread( fid, nrr, 'float32');


%Each record holds data from one source depth/receiver depth pair

tlt = zeros( nrd, nrr, nsd );

for i = 1:nsd
  %disp(['Reading data for source ' num2str(i) ' of ' num2str(nsd)])
  for j = 1:nrd
    recnum = 6 + (i-1)*nrd + j; 
    fseek(fid, (recnum-1)*4*recl, -1);      %Move to end of previous record
 
    temp = fread(fid, 2*nrr, 'float32');    %Read complex data
    tlt(j, :, i) = temp( 1:2:2*nrr ) + sqrt(-1)*temp(2:2:2*nrr); 
    %Transmission loss matrix indexed by  rd x rr x sd

  end
end

fclose(fid);