One way to do this is to use coder.ceval and the C runtime functions. Alternatively, the MATLAB functions FOPEN, FREAD, FCLOSE are all supported for code generation. So you could use those to read the file in to a MATLAB string, and then use coder.ceval to call sscanf to parse the string.
If you want to use the C runtime, and supposing that the file is named data.txt and that it contains 201-by-201 (201 lines of 201) space-delimited doubles (e.g. output from dlmwrite('data.txt',reshape(1:(201^2),201,201),'delimiter',' '); ) you could use something like:
function y = parsefile
%#codegen
coder.cinclude('<stdio.h>');
f = coder.opaque('FILE*','NULL');
f = coder.ceval('fopen', cstr('data.txt'),cstr('r'));
assert(f ~= coder.opaque('FILE*','NULL'), 'Failed to open file');
% Parse file
N = 201;
y = coder.nullcopy(zeros(N,N));
fmt = cstr('%lf ');
for k = 1:numel(y)
coder.ceval('fscanf', f, fmt, coder.wref(y(k)));
end
coder.ceval('fclose',f);
% File was read in row-major order so transpose
y = y.';
%--------------------------------------------------------------------------
function s = cstr(st)
% Append a \0 (NUL) character to produce a C
% string from a MATLAB string
s = [st, 0];
Just run:
codegen parsefile
y = parsefile_mex;
to use it.
