linear_operator: Create a block-native linear operator.

In eigencore: Certified Partial Eigenvalue and Singular Value Computation

Create a block-native linear operator.

Description

Create a block-native linear operator.

Usage

linear_operator(
  dim,
  apply,
  apply_adjoint = NULL,
  dtype = "double",
  structure = general(),
  name = NULL,
  metadata = list()
)

Arguments

dim	Integer vector of length two giving row and column dimensions.
apply	Function implementing block multiplication by the operator.
apply_adjoint	Optional function implementing block multiplication by the adjoint operator.
dtype	Scalar character type label, currently "double" or "complex".
structure	Eigencore structure descriptor such as general() or hermitian().
name	Optional operator label used in plans and diagnostics.
metadata	Optional list of implementation metadata.

Value

An eigencore_operator list containing dimensions, apply callbacks, scalar type, structure metadata, a display name, and implementation metadata.

Examples

A <- diag(c(3, 2, 1))
op <- linear_operator(
  dim = dim(A),
  apply = function(X, alpha = 1, beta = 0, Y = NULL) {
    Z <- alpha * (A %*% X)
    if (is.null(Y) || beta == 0) Z else Z + beta * Y
  },
  structure = hermitian(),
  metadata = list(frobenius_norm = sqrt(sum(A^2)))
)
fit <- eig_partial(op, k = 1, target = largest())
values(fit)

eigencore documentation built on July 26, 2026, 1:06 a.m.