Virtual Class of Triangular Matrices in package:Matrix

Description

The virtual class of triangular matrices,"triangularMatrix", from the package Matrix contains numeric and logical, dense and sparse matrices, e.g., see the examples.

The main use will be in methods (and C functions) that can deal with all triangular matrices.

Slots

uplo:

String (of class "character"). Must be either "U", for upper triangular, and "L", for lower triangular.

diag:

String (of class "character"). Must be either "U", for unit triangular (diagonal is all ones), or "N" for non-unit. The diagonal elements are not accessed internally when diag is "U". For denseMatrix classes, they need to be allocated though, i.e., the length of the x slot does not depend on diag.

Dim, Dimnames:

The dimension (a length-2 "integer") and corresponding names (or NULL), inherited from the Matrix, see there.

Extends

Class "Matrix", directly.

Methods

There's a C function triangularMatrix_validity() called by the internal validity checking functions.

Currently, Schur, isSymmetric and as() (i.e. coerce) have methods with triangularMatrix in their signature.

See Also

Classes symmetricMatrix, and, e.g., dtrMatrix for numeric dense matrices, or ltCMatrix for a logical sparse matrix subclass of "triangularMatrix".

Examples

showClass("triangularMatrix")

## The names of direct subclasses:
scl <- getClass("triangularMatrix")@subclasses
directly <- sapply(lapply(scl, slot, "by"), length) == 0
names(scl)[directly]