Question

I am new matlab user.
Now, I’am doing my work by using matlab software. but I have problem to improve my code in order to have fast time execution.
right now, I have to make a matrix(A,10,C)) which has the value integer [ 1 10].
currently, I am using logic randperm. here my code :

for c=1:C,
   for a=1:A,
       result(a,:,c)=randperm(10);
   end
end

but when I tried to analyze with profile viewer. That code take a more time.

so I wish that there is someone want to share his/her experience about this.
thanks you.
regard

Answer 1

Here’s an alternate solution but it does not have the nice properties of randperm regarding the distribution of your random numbers:

[~,result_alt] = sort( rand(A,10,C) , 2);

A quick profile shows that your method takes approximately 1.6e-3 seconds on average when A = C = 10 whereas this method takes 5.6e-5 seconds on average.

Note:

Older version of MATLAB won’t support the ~ operator. If so, try:

[vals result_alt] = sort( rand(A,10,C) , 2);

and ignore vals.