Fread problem...

Hello to everyone!

I have a problem with the following simple portion of code:

b = rand(5, 1);

fid = fopen('prova.bin', 'w');
fwrite(fid, b);
fclose(fid);

% Read the contents back into an array
fid = fopen('prova.bin');
B = fread(fid, 5, 'double');
fclose(fid);

Fread doesn't seem to work, how come ? Has any of you got an idea?

Thank you very much and my best regards! Jason.

Answer 1

[Thomas]

Add type 'double' in your fwrite

b = rand(5, 1);

fid = fopen('prova.bin', 'w');
fwrite(fid, b,'double');       % add type double here
fclose(fid);

% Read the contents back into an array
fid = fopen('prova.bin');
B = fread(fid, 5, 'double');
fclose(fid);

should work

Answer 2

[Bård Skaflestad]

You need to specify the precision of the data you output using fwrite is double. Otherwise, the subsequent fread operation fail. I'd write the above as

b = rand(5, 1);
fid = fopen('prova.bin', 'w');
fwrite(fid, b, 'double');
fclose(fid);
% Read the contents back into an array
fid = fopen('prova.bin');
B = fread(fid, 5, 'double');
fclose(fid);