Inspect an amQR factorization object

Returns a named list of metadata fields describing an amQR factor produced by am_qr().

Usage

qr_info(qr)

Arguments

qr

An amQR object.

Value

A named list with the following elements:

rank

Integer effective rank of the factored matrix.

dim

Integer vector of length 2: c(nrow, ncol) of the source matrix.

thin

Logical; TRUE when a thin (economy) QR was computed.

pivoted

Logical; TRUE when column pivoting was used.

pivot

Integer permutation vector, or NULL when unpivoted.

representation

Character string describing the internal storage format.

backend_ops

Character string naming the backend that owns any resident buffers, or NULL.

backend

Character string: the preferred backend.

precision

Character string: "strict" or "fast".

method

Character string: QR algorithm used.

compact_factor_available

Logical.

compact_factor_source

Character string or NULL.

compact_factor_materialized

Logical.

q_materialized

Logical.

r_materialized

Logical.

See also

am_qr, qr_downdate

Examples

X <- adgeMatrix(matrix(rnorm(30), nrow = 6))
qf <- am_qr(X)
info <- qr_info(qf)
info$rank
#> [1] 5