diagrv#

Purpose#

Inserts a vector into the diagonal of a matrix.

Format#

y = diagrv(x, v)#

Parameters:

x (NxK matrix) – Data matrix.
v (min(N,K)x1 vector.) – Vector to replace the diagonal in x with.

Returns:

y (NxK matrix) – equal to x with its principal diagonal elements equal to those of v.

Examples#

// Set rng seed for reproducibility
rndseed 458716;

// Build random x matrix
x = rndu(3, 3);

// Vector of ones to put in diagonal
v = ones(3,1);

// Call diagrv
y = diagrv(x, v);

After the code above:

    0.967 0.318 0.465     1.000     1.000 0.318 0.465
x = 0.046 0.786 0.205 v = 1.000 y = 0.046 1.000 0.205
    0.738 0.305 0.734     1.000     0.738 0.305 1.000

Remarks#

diag() reverses the procedure and pulls the diagonal out of a matrix.

Use bandrv() to create a diagonal matrix from a vector.