Highly Challenging Problem : Delete a matrix from a binary file after reading it.

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AMEHRI WALID 2019-12-9

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Hello Everyone,

I want to store matrices into a binary file, the in a second time, for another process, I wan to read the matrices one-by-one from the binary file.

But, since when I read a matrix I can store it into a variable, I don't need it anymore holding memory in my binary file.

clear; clc; close; warning('off','all'); fclose('all');
delete 'All_K.bin'
% Write Part
N   =  5;
n   =  3;
K1  =  3*ones(N * n);
K2  =  5*ones(N * n);
K3  =  9*ones(N * n);
fileID  =  fopen('All_K.bin', 'a');
fwrite(fileID, K1, 'double');
fwrite(fileID, K2, 'double');
fwrite(fileID, K3, 'double');
fclose(fileID);
% Read Part 
fid  =  fopen('All_K.bin', 'r');
% Read K1 from the file
A1  =  fread(fid, [N*n N*n], 'double');
% Erase K1 from the file
% ******************************* %
% Read K2 from the file
A2  =  fread(fid, [N*n N*n], 'double');
% Erase K2 from the file
% ******************************* %
% Read K3 from the file
A3  =  fread(fid, [N*n N*n], 'double');
% Erase K3 from the file
% ******************************* %
fclose(fid);

So, please can Anyone help me solve this difficult problem.

Thanks in advance!

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James Tursa 2019-12-9

"Deleting" a section of a binary file amounts to rewriting the file, and reading/writing files to disk is one of the slowest things a computer does. Better to follow the suggestions made to avoid this. If you really need it in a raw binary form, try to read them sequentially.

AMEHRI WALID 2019-12-9