MATLAB: Checking file or data integrity

checksumMATLAB

G'day mates, I am collecting data from a multi-channel DAQ, therefore, the datasets tend to be quite large. I am splitting each channel out from the lumped data into its own respective vector and saving an interim copy as a .mat binary. Is there a way to verify that the data saved in the .mat binary and the vector in memory are identical? i.e. ( in pseudo-code )
A = [ channel 1 ]
A_check = checksum (a)
save A as A.mat
A.mat_check = checksum(A.mat)
assert {
A_check equals A.mat_check
} throw exception e1 CheckSumsDoNotMatch
if (A_check != A.mat_check)
...try again...
Cheers.

Best Answer

Maybe with FEX: DataHash or FEX: GetMD5:
A = rand(1, 1e6);
A_check = DataHash(A); % Or: GetMD5(a, 'Binary')
save('A.mat', A);
FileData = load('A.mat');
A_reloaded_check = DataHash(FileData.A);
if ~isequal(A_check, A_reloaded_check)
error('Saving failed!');
end
You should definitely stop with an error. If the saving fails, there is a severe problem, which cannot be handled reliably by repeating. Either the disk is damaged or the CPU melts down.
[EDITED] Guillaume is right: Calculating the checksums has no advantage. I suggested it only, because there might be a need anywhere, which was not mentioned in the question. An efficient version of my code would be:
A = rand(1, 1e6);
save('A.mat', A);
FileData = load('A.mat');
if ~isequal(A, FileData.A)
error('Saving failed!');
end