How to Convert 2D matrix to 3D with time as 3rd dimension

I have a code which results in a 2D matrix .The code is in a loop . So I get many 2D matrix values. I want to convert it into a 3D matrix with 3rd Dimension as time. How can I do this ?

Answer 1

[Azzi Abdelmalek]

 A(:,:,k)=B

[Venkata Jayadeep Kodali]

I want K to be the time. shall I use tic toc command ?

[Azzi Abdelmalek]

You can not, K should be a positive integer

[Venkata Jayadeep Kodali]

Then how can I do it with respect to time

[James Tursa]

Add a line:

the_time(k) = whatever format of time you want to store

Reminder that best practice would be to pre-allocate A and the_time.

[Venkata Jayadeep Kodali]

what does that mean @james. I did not understand your answer.

[Evan]

Do you mean you want B to be the time? If so, yes, tic/toc would work. You would call tic outside the loop then have something like this inside:

   A(:,:,k) = toc;

[Azzi Abdelmalek]

You can also use a struct format

for k=1:5
  A=rand(4); % for example
  data(k).time=k  % for example
  data(k).matrix=A
end

Answer 2

[Youssef Khmou]

hi,

You can the method provided above, but the function "toc" may have problems , i propose using an integer variable , here is an example :

% Eeach time we get a 2D AWGN matrix with different Standard Deviation

 N=100;
 L=200;
 for n=1:N
      r=rand;
      M(:,:,n)=r*randn(L);
 end

If your loop indexes start differently( negative values per example , try this solution :

 N=100;
L=200;
time=1;
for n=-10:N

      r=rand;
      M(:,:,time)=r*randn(L);
      time=time+1;
end