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)
#> [1] 3