Matrix (version 1.2-8)

symmetricMatrix-class: Virtual Class of Symmetric Matrices in Package Matrix

Description

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

The main use is in methods (and C functions) that can deal with all symmetric matrices.

Slots

Extends

Class "Matrix", directly.

Methods

There's a C function symmetricMatrix_validate() called by the internal validity checking functions, and also from getValidity(getClass("symmetricMatrix")).

Validity and <code><a rd-options="" href="/link/dimnames?package=Matrix&version=1.2-8" data-mini-rdoc="Matrix::dimnames">dimnames</a></code>

The validity checks do not require a symmetric Dimnames slot, so it can be list(NULL, ), e.g., for efficiency. However, dimnames() and other functions and methods should behave as if the dimnames were symmetric, i.e., with both list components identical.

See Also

isSymmetric which has efficient methods (isSymmetric-methods) for the Matrix classes. Classes triangularMatrix, and, e.g., dsyMatrix for numeric dense matrices, or lsCMatrix for a logical sparse matrix class.

Examples

## An example about the symmetric Dimnames:
sy <- sparseMatrix(i= c(2,4,3:5), j= c(4,7:5,5), x = 1:5, dims = c(7,7),
                   symmetric=TRUE, dimnames = list(NULL, letters[1:7]))
sy # shows symmetrical dimnames
sy@Dimnames  # internally only one part is stored
dimnames(sy) # both parts - as sy *is* symmetrical

showClass("symmetricMatrix")

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

## Methods -- applicaple to all subclasses above:
showMethods(classes = "symmetricMatrix")