Generic helper for Z^T A Z using an operator.

Generic helper for Z^T A Z using an operator.

Usage

gram_Z_A_Z(Zop, A, block_size = 64L)

Arguments

Zop

Matrix-free operator.

A

Sparse or diagonal matrix compatible with Z columns.

block_size

Number of columns processed per batch.

Value

Symmetric dense matrix.

Examples

# \donttest{
library(Matrix)
K1 <- Matrix(rnorm(20), 10, 2)
Zop <- make_Zop_from_Ks(list(K1))
A <- Diagonal(10, 1)
G <- gram_Z_A_Z(Zop, A)
# }