diag: Extract or construct a diagonal for HDF5Matrix

In BigDataStatMeth: Title: Scalable Statistical Computing with HDF5-Backed Matrices

Extract or construct a diagonal for HDF5Matrix

Description

Overrides base::diag() to dispatch on HDF5Matrix objects. For plain R matrices/vectors the call is forwarded to base::diag().

When x is an HDF5Matrix, extracts the diagonal as an in-memory numeric vector (length = min(nrow, ncol)).

Usage

diag(x, ...)

## Default S3 method:
diag(x, nrow, ncol, names = TRUE, ...)

## S3 method for class 'HDF5Matrix'
diag(x, ...)

Arguments

x	An HDF5Matrix or any object accepted by base::diag().
...	Ignored.
nrow	Passed to base::diag() for non-HDF5Matrix objects.
ncol	Passed to base::diag() for non-HDF5Matrix objects.
names	Passed to base::diag() for non-HDF5Matrix objects.

Value

For HDF5Matrix: numeric vector of diagonal elements. For plain R objects: result of base::diag().

See Also

diag

BigDataStatMeth documentation built on May 15, 2026, 1:07 a.m.