Mar 9, 2011 · diag is the normal MATLAB solution (as pointed out by posdef.) Thus. D = diag(vec); gives you a matrix with diagonal elements as needed. Perhaps better in some applications is to create a sparse matrix, since a diagonal matrix is quite sparse. So if you are doing matrix multiplies this will greatly help in reducing the number of unnecessary ...

Suppose I have an NxN matrix A, an index vector V consisting of a subset of the numbers 1:N, and a value K, and I want to do this: for i = V A(i,i) = K end Is there a way to do this in one statement w/ vectorization? e.g. A(something) = K. The statement A(V,V) = K will not work, it assigns off-diagonal elements, and this is not what I want. e.g.:

May 4, 2013 · I have a matrix K of dimensions n x n. I want to create a new block diagonal matrix M of dimensions N x N, such that it contains d blocks of matrix K as its diagonal. I would have directly used M = blkdiag(K,K,K) etc. had d been smaller.

Sep 16, 2013 · Diagonal matrix in matlab. Hot Network Questions In Canada's 2025 election, what have either Poilievre or ...

Nov 15, 2016 · I am interested how to create a diagonal matrix from an array of matrices. I created an array of matrices in MATLAB: X<62x62x1000> it consists of 1000 matrices with dimensions 62x62. I want to create a matrix of dimensions 62000x62000 with 1000 sub matrices from array X along main diagonal.

Mar 28, 2013 · You need to modify the entry of A for your function to return anything more than the zero matrix. You could use MATLAB's function diag which creates a diagonal matrix from a vector. for example. d=1:n; %# create vector 1,2,...,n A = diag(d) %# create diagonal matrix with entries A(i,i) = i with i=1,2,...,n; modify the input vector d to suite ...

May 22, 2020 · I would like to create a block diagonal matrix from another matrix. Let's say the H matrix is a 4 by 4 matrix and I want to create a matrix that is 5 by 5 with the upper left part being the H matrix. and the lower bottom part being 5. The other parts in the matrix are all …

Jul 18, 2016 · Keep in mind that you need u to be in the right length of the k diagonal you want, so if the final matrix is n*n, the k's diagonal will have only n-abs(k) elements. For you case: n = 5; % the size of the matrix v = ones(n,1)-2; % make the vector for the main diagonal u = ones(n-1,1)*4; % make the vector for +1 and -1 diagonal A5 = diag(v)+diag ...

Aug 12, 2019 · n = 5; % matrix size M = reshape(1:n*n,n,n); % matrix with linear indices indices = diag(M, ii); % indices to diagonal ii However, it is much easier to just compute the right indices directly. As discovered by OP, the upper diagonal elements are given by:

Nov 28, 2012 · % A is a 15 x 15 matrix, want to zero out {1,2,3,8}th elements on the diagonal d = diag(A); % diagonal elements of A d([4:7 9:15]) = 0; % zero out the elements you want to KEEP A = A - diag(d); % diag d is a diagonal matrix with d on the main diagonal But it would be easier with a for loop: for i=[1,2,3,8] A(i,i) = 0; end