determine the limit of txt file while using regexp

content = fileread( 'trial.txt' ) ;
matches = regexp( content, '[-\d\.]+(?=-\d)', 'match' ) ;
data    = str2double( matches );

% With above commands, I extract the specific numeric values in the attached file. But I need to limit this search from %beginning to "START OF RMS MAP" (line 32, but this number is variable) not all lines. How can I set the this last line while I'm using regexp.

[Cedric]

Stephen's approach is the best, but if you can't figure out how to adapt it to your case and need to work out a solution quickly, you can always do

 content = strsplit( fileread( 'trial.txt' ), 'START OF RMS MAP' ) ;
 data    = str2double( regexp( content{1}, '[-\d\.]+(?=-\d)', 'match' )) ;

PS: if this question is still about extracting only the numbers mentioned in this thread, you should have made it clear initially, because Stephen wrote a complete solution for extracting all numbers within the section that you mention.

[sermet]

Thank you Cedric.

Answer 1

[Stephen23]

It is often faster and easier just to read in all of the data from a file, then then use simple indexing to pick the bits that you need. This will read the first part of the file:

opt = {'CollectOutput',true};
fid = fopen('trial.txt','rt');
C_date = textscan(fid,'%f%f%f%f%f%f%*s',1,'HeaderLines',5,opt{:});
for k = 1:4
    C_lat(k,:) = textscan(fid,'%f%f%f%f%f%*s',1,'Delimiter','- ',opt{:});
    C_map(k,:) = textscan(fid,repmat('%f',1,16),5,opt{:});
end
fclose(fid);

[sermet]

when I use celldisp(C_lat) to see the numbers, there are all empty arrays of C_lat have been seen. How can I convert to doubles for C_lat?

[Stephen23]

I do not understand your request. When I run that code using your file I get these outputs:

>> celldisp(C_lat)
C_lat{1} =
    87.5000   180.0000   180.0000     5.0000   450.0000
C_lat{2} =
    85   180   180     5   450
C_lat{3} =
    82.5000   180.0000   180.0000     5.0000   450.0000
C_lat{4} =
    80   180   180     5   450

And similarly for C_map:

>> celldisp(C_map)
C_map{1} =
   259   260   262   263   264   265   265   266   266   266   266   266   265   264   262   261
   259   257   254   252   249   245   242   239   235   231   228   224   221   217   214   211
   208   206   203   201   200   198   198   197   197   197   197   198   198   200   201   203
   205   207   209   211   214   216   219   221   224   226   229   232   234   237   239   242
   244   246   248   250   252   254   256   257   259   NaN   NaN   NaN   NaN   NaN   NaN   NaN
C_map{2} =
   266   268   271   274   276   279   281   283   285   287   288   289   289   288   287   285
   282   278   273   268   262   255   248   240   232   224   216   208   200   193   186   179
   ....

You can access the elements of a cell array using indexing:

http://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-cell-array.html