nsyMatrix-class {Matrix} | 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, *in*directly, use
`showClass("nsyMatrix")`

, e.g., for details.

### Methods

Currently, mainly `t()`

and coercion methods (for
`as(.)`

; use, e.g.,
`showMethods(class="dsyMatrix")`

for details.

### See Also

`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
```

[Package

*Matrix* version 1.5-1

Index]