eig_partial: Compute a partial eigendecomposition.

In eigencore: Certified Partial Eigenvalue and Singular Value Computation

Compute a partial eigendecomposition.

Description

Compute a partial eigendecomposition.

Usage

eig_partial(
  A,
  k,
  target = largest(),
  B = NULL,
  method = auto(),
  tol = 1e-08,
  maxit = NULL,
  vectors = TRUE,
  seed = NULL,
  certify = TRUE,
  allow_dense_fallback = c("auto", "never", "always")
)

Arguments

A	Matrix or eigencore operator.
k	Number of eigenpairs to compute.
target	Eigencore eigenvalue target descriptor.
B	Optional metric matrix or operator for generalized problems.
method	Solver method descriptor.
tol	Convergence and certification tolerance.
maxit	Optional iteration limit.
vectors	Whether to compute vectors.
seed	Optional random seed for stochastic solver components.
certify	Whether to compute certification diagnostics.
allow_dense_fallback	Dense fallback policy.

Value

An eigencore_eigen_result containing computed values, optional vectors, certificate diagnostics, method/plan metadata, and convergence diagnostics.

Examples

A <- diag(c(5, 4, 3, 2, 1))
A[1, 2] <- A[2, 1] <- 0.1
fit <- eig_partial(A, k = 2, target = largest())
values(fit)
certificate(fit)$passed

# Generalized SPD problem A x = lambda B x
B <- diag(c(2, 1, 1, 1, 1))
gfit <- eig_partial(A, B = B, k = 2, target = smallest())
values(gfit)

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