sym_of_vechs: Symmetric matrix A from vechs(A)

In jeksterslab/strRegression: Structure of Regression

Description

Symmetric matrix from its strict half-vectorization.

Usage

sym_of_vechs(x, diags)

Arguments

x	Vector.
diags	Vector. Diagonal elements.

Details

Generates an m \times m symmetric matrix from an (m(m + 1) / 2) - m vector. The m \times 1 vector of diagonal values should be supplied.

Value

A vector.

Author(s)

Ivan Jacob Agaloos Pesigan

References

Wikipedia: Half-vectorization

See Also

Other Linear Algebra Functions: dcap(), sym_of_vech(), vechnames(), vechsnames(), vechs(), vech()

Examples

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

sym_of_vechs(vechsA, diags = 1)

jeksterslab/strRegression documentation built on Dec. 20, 2021, 10:12 p.m.