How to increase the size of a matrix within for loop

Hello

There is a for loop in my code.

imagine i obtain value 1 after the first iteration, so it would be my first array in the matrix CM--->so CM=[1]

then in the second iteration i obtain: [1 0.214; 0.214 1] which i want to be added to the matrix CM as

CM= [1 0 0;

0 1 0.214;

0 0.214 1]

then in the third iteration i obtain: [1 0 0; 0 1 0.0013; 0 0.0013 1] , so the matrix CM should become:

CM= [1 0 0 0 0 0;

0 1 0.214 0 0 0;

0 0.214 1 0 0 0;

0 0 0 1 0 0;

0 0 0 0 1 0.0013

0 0 0 0 0.0013 0]

and so forth.

How can i formulate this? Any help is highly appreciated.

Answer 1

[Steven Lord]

Consider creating a cell array to store the pieces you want to be placed on the main diagonal. When you want to assemble the matrix call blkdiag, creating a comma-separated list of input arguments using the cell array.

C = {1, [1 2;2 1], [1 2 3; 2 3 1; 3 1 2]};
P = blkdiag(C{1})

P = 1

Q = blkdiag(C{1:2})

Q = 3×3

1 0 0 0 1 2 0 2 1

R = blkdiag(C{1:3})

R = 6×6

1 0 0 0 0 0 0 1 2 0 0 0 0 2 1 0 0 0 0 0 0 1 2 3 0 0 0 2 3 1 0 0 0 3 1 2

S = blkdiag(C{:})

S = 6×6

1 0 0 0 0 0 0 1 2 0 0 0 0 2 1 0 0 0 0 0 0 1 2 3 0 0 0 2 3 1 0 0 0 3 1 2

[Pooneh Shah Malekpoor]

Great! Could you please tell me how can i store each of the cell arrays in the matrix C? i mean how can i ask matlab to store [ 1 2;2 1] in the second array of C, then store [1 2 3; 2 3 1; 3 1 2] in the third array and so forth?

C = {1, [1 2;2 1], [1 2 3; 2 3 1; 3 1 2]}