Transform an upper triangle-stored matrix to a sparse one

Transform an upper triangle-stored matrix to a sparse one

Usage

upper_triangle_to_sparse(upper_triangle_vals, shift, n, type = c("csc", "csr"))

Arguments

upper_triangle_vals

Numerical vector. The values of the upper triangle stored in a row major format.

shift

Boolean. Did you exclude the diagonal.

n

Integer. Number of columns and rows of the symmetric matrix.

type

String. One of c("csc", "csr"). Which type of of sparse matrix to return.

Value

The sparse matrix.

Examples

# 3 x 3 symmetric matrix from its off-diagonal upper triangle
mat <- upper_triangle_to_sparse(c(0.5, 0.2, 0.8), shift = TRUE, n = 3L)
dim(mat)
#> [1] 3 3