Construct a supplied Gram PSD factor — psd_gram

Dense base and dgeMatrix inputs receive a complete compact-SVD certificate and canonical spectral actions. A dgCMatrix remains sparse and exposes only the form and Gram actions justified by K = L L^T or K = L^T L; sparse storage alone does not certify rank or a principal square root.

Usage

psd_gram_factor(
  x,
  orientation = c("columns", "rows"),
  policy = psd_policy(),
  source = c("snapshot", "live")
)

Arguments

x: A finite real-double base matrix, dgeMatrix, or dgCMatrix.
orientation: Whether columns define K = x x^T or rows define K = x^T x.
policy: A PSD policy.
source: Source ownership.

Value

A certified PSD factor when the representation is admitted.