Obtaining an updated diagonal Matrices

Good day everyone. Pls, can someone assist on generating a diagonal matrices from each row of a random matrix as: M=rand(N,2) where N=20 iterations =300 The matrices i want to generate, at first is, for iter=1:iterations for i=1:N generate a diagonal matrices of 2x2 from M i.e 20 diagonal matrices of size 2x2.

for the update matrices meaning the first ones are previous, so the update or current matrices should be for j=2:iterations-1 for i=1:N generate a 20 diagonal matrices of size 2x2 up to j, Let say something like P(i, ,j)=diag(, ,j) where P(i, ,j) are the current generated 20 diagonal matrices of 2x2 up to j. Thank you. Best regards,

Answer 1

[Andrei Bobrov]

N=20;
itr = 300;
i1 =...
    bsxfun(@plus,bsxfun(@plus,1:4:4*N,[0;3]),reshape(0:4*N:(itr-1)*4*N,1,1,[]));
out = zeros(2,2,N,itr);
M=rand(N*itr,2);
out(i1) = M.';

[Abul A]

I am much grateful Mr. andrei bobrov, big kudos. It really generated the matrices but i want to it, to be like if,

N=20;

iterations=300;

M=rand(N,2);

for iter=1:iterations

for i=1:N

G(i,:,1)=diag(M( ));

meaning it will generate a 20 diagonal matrices of 2x2 for the iter=1:300 and for i=1:N

then the next

for j=2:iter-1 or for j=2:299

for i=N

G(i,:,j)=diag(M(, ,j))

meaning for j=2:299 and for i=1:20 it will generate 20 diagonal matrices of 2x2 each iteration upto j . Instead of doing it one by one. Hope i put it clear. Once more thanks