diag_of_vech: Diagonals of A from vech(A)
In jeksterslab/linearAlgebra: Linear Algebra with R

Description Usage Arguments Details Author(s) References See Also Examples

View source: R/linearAlgebra-diag_of_vech.R

Diagonals of a matrix from its half-vectorization.

1	diag_of_vech(x, loc = FALSE)

`x`	Vector. Half-vectorization of a `k` by `k` matrix.
`loc`	Logical. If `loc = TRUE`, return the location of the diagonal elements in the input vector. If `loc = FALSE`, return the values of the diagonal elements.

Generates a vector of length k of diagonal elements or location in the input vector of an k \times k matrix.

Ivan Jacob Agaloos Pesigan

Wikipedia: Half-vectorization

Other Vectorization Functions: vec_mean(), vechnames(), vechsnames(), vechs(), vech(), vec()

A <- matrix(
  data = c(
    1.0, 0.5, 0.4,
    0.5, 1.0, 0.6,
    0.4, 0.6, 1.0
  ),
  ncol = 3
)
vechA <- c(1.0, 0.5, 0.4, 1.0, 0.6, 1.0)

diag_of_vech(vechA, loc = FALSE)
diag_of_vech(vechA, loc = TRUE)