matlab storing data using nested for loop

here is my problem:

I have raw data which is 3D ARRAY with (x,y,t) where x,y are points and t is # of samples

I want to take signals (512 samples) from 51x51, total 2601 different points and add those signals so that i can take the average

Thus, I want an array of the dimension 2601x512(512x2601 will also do i guess) and later I am planning to use 'sum' so that i can get 1x512 data

Here is what I have tried:

for iii = 1:51
    for jjj = 1:51
       for kkk = 1:2601
          new_sig(kkk,:)=uwpi(294+iii,274+jjj,:);
          % uwpi is my raw data and (294,274) is my starting point
       end
   end
end

when i do this, i get 2601x512 matrix but every row is identical which is not possible

when I try:

for iii = 1:51
    for jjj = 1:51
        new_sig(iii*jjj,:)=uwpi(294+iii,274+jjj,:);
    end
end

In this case, some rows of new_sig have only 0s (I think this happens because of iii*jjj term)

I've also tried to use squeeze command but wasn't really getting anywhere

Can anyone point me to the right direction?

If there is a better way to do this without nested for loop, that's fine too

Thank you

Answer 1

[Emmanouil Tzorakoleftherakis]

Hi JoonHee,

In line

new_sig(kkk,:)=uwpi(294+iii,274+jjj,:);

you are attempting to assign a comma-separated list to a 2D matrix. Try changing that to

new_sig(kkk,:)=permute(uwpi(294+iii,274+jjj,:),[1 3 2]);