nex_int

 nex_int(filename, varname): Read interval variable from a .nex file

 [n, ts_left, ts_right] = nex_int(filename, varname)

 INPUT:
   filename - if empty string, will use File Open dialog
   varname - variable name
 OUTPUT:
   n - number of intervals
   ts_left - array of left ends of the intervals (in seconds)
   ts_right - array of right ends of the intervals (in seconds)

0001 function [n, ts_left, ts_right] = nex_int(filename, varname)
0002 % nex_int(filename, varname): Read interval variable from a .nex file
0003 %
0004 % [n, ts_left, ts_right] = nex_int(filename, varname)
0005 %
0006 % INPUT:
0007 %   filename - if empty string, will use File Open dialog
0008 %   varname - variable name
0009 % OUTPUT:
0010 %   n - number of intervals
0011 %   ts_left - array of left ends of the intervals (in seconds)
0012 %   ts_right - array of right ends of the intervals (in seconds)
0013 
0014 n = 0;
0015 ts_left = 0;
0016 ts_right = 0;
0017 
0018 if(nargin ~= 2)
0019    disp('2 input arguments are required')
0020    return
0021 end
0022 
0023 if(ischar(filename) == 0)
0024    disp('input arguments should be character arrays')
0025    return
0026 end
0027 
0028 if(ischar(varname) == 0)
0029    disp('input arguments should be character arrays')
0030    return
0031 end
0032 
0033 if(isempty(filename))
0034    [fname, pathname] = uigetfile('*.nex', 'Select a Nex file');
0035     filename = strcat(pathname, fname);
0036 end
0037 
0038 fid = fopen(filename, 'r');
0039 if(fid == -1)
0040     disp('cannot open file');
0041    return
0042 end
0043 
0044 disp(strcat('file = ', filename));
0045 magic = fread(fid, 1, 'int32');
0046 version = fread(fid, 1, 'int32');
0047 comment = fread(fid, 256, 'char');
0048 freq = fread(fid, 1, 'double');
0049 tbeg = fread(fid, 1, 'int32');
0050 tend = fread(fid, 1, 'int32');
0051 nvar = fread(fid, 1, 'int32');
0052 fseek(fid, 260, 'cof');
0053 name = zeros(1, 64);
0054 found = 0;
0055 for i=1:nvar
0056     type = fread(fid, 1, 'int32');
0057     var_version = fread(fid, 1, 'int32');
0058     name = fread(fid, [1 64], 'char');
0059     offset = fread(fid, 1, 'int32');
0060     n = fread(fid, 1, 'int32');
0061     name = char(name);
0062     name = deblank(name);
0063     k = strcmp(name, deblank(varname));
0064     if(k == 1)
0065         if type ~= 2
0066             disp(sprintf('%s is not an interval variable', deblank(varname)));
0067             return;
0068         end
0069         found = 1;
0070         fseek(fid, offset, 'bof');
0071         ts_left = fread(fid, [1 n], 'int32');
0072         ts_right = fread(fid, [1 n], 'int32');
0073         break
0074     end
0075     dummy = fread(fid, 128, 'char');
0076 end
0077 
0078 fclose(fid);
0079 
0080 if found == 0
0081     disp('did not find variable in the file');
0082 else
0083     ts_left = ts_left/freq;
0084     ts_right = ts_right/freq;
0085     disp(strcat('number of intervals = ', num2str(n)));
0086 end