# nsyMatrix-class: Symmetric Dense Nonzero-Pattern Matrices In Matrix: Sparse and Dense Matrix Classes and Methods

 nsyMatrix-class R Documentation

## Symmetric Dense Nonzero-Pattern Matrices

### Description

The "nsyMatrix" class is the class of symmetric, dense nonzero-pattern matrices in non-packed storage and "nspMatrix" is the class of of these in packed storage. Only the upper triangle or the lower triangle is stored.

### Objects from the Class

Objects can be created by calls of the form new("nsyMatrix", ...).

### Slots

uplo:

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

x:

Object of class "logical". The logical values that constitute the matrix, stored in column-major order.

Dim,Dimnames:

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

factors:

Object of class "list". A named list of factorizations that have been computed for the matrix.

### Extends

"nsyMatrix" extends class "ngeMatrix", directly, whereas
"nspMatrix" extends class "ndenseMatrix", directly.

Both extend class "symmetricMatrix", directly, and class "Matrix" and others, indirectly, use showClass("nsyMatrix"), e.g., for details.

### Methods

Currently, mainly t() and coercion methods (for as(.); use, e.g., showMethods(class="dsyMatrix") for details.

ngeMatrix, Matrix, t

### Examples

(s0 <- new("nsyMatrix"))

(M2 <- Matrix(c(TRUE, NA, FALSE, FALSE), 2, 2)) # logical dense (ltr)
(sM <- M2 & t(M2)) # "lge"
class(sM <- as(sM, "nMatrix"))         # -> "nge"
(sM <- as(sM, "symmetricMatrix")) # -> "nsy"
str  (sM <- as(sM, "packedMatrix"))    # -> "nsp": packed symmetric

Matrix documentation built on Nov. 11, 2022, 9:06 a.m.