getting '0F' instead of 'F' for dec2hex(15)

I want to apply dec2hex function to a very large matrix. For a reason which is beyond the scope of this question, I need to get '0F' instead of 'F' for dec2hex(15). Since the running time is a matter, I want to find a time-efficient method to fix this problem.

Answer 1

[Jan]

dec2hex(15, 2)
% >> 0F

Of course such tricks are explained in the documentation ( help dec2hex ), so it is worth to read it before posting in the forum.

sprintf is slightly faster than dec2hex:

sprintf('%02x', 15)

x = randi([0, 255], 1, 1e3);
tic, for k=1:100, s = dec2hex(x, 2); end, toc
tic, for k=1:100, s = sprintf('%02x', x); end, toc

 Elapsed time is 0.069916 seconds.
 Elapsed time is 0.052959 seconds.

While dec2hex replies a CHAR-matrix, sprintf creates a CHAR vector, which might be more useful.

[Ronaldo]

dec2hex(15)='F' while sprintf('%02x', 15)='0f'. I check that hex2dec('0F')==hex2dec('0f'). I was wondering if you confirm that there is no difference between capital and small letters in dec2hex and reverse conversion. Also is there anyway that I can get capital letters.

[Walter Roberson]

There is no difference between capital and small letters in hex2dec().

To get uppercase out of sprintf(), use X instead of x. %02X instead of %02x