ntrMatrix-class {Matrix} | R Documentation |

## Triangular Dense Logical Matrices

### Description

The `"ntrMatrix"`

class is the class of triangular, dense,
logical matrices in nonpacked storage. The `"ntpMatrix"`

class
is the same except in packed storage.

### Slots

`x`

:Object of class `"logical"`

. The logical
values that constitute the matrix, stored in column-major order.

`uplo`

:Object of class `"character"`

. Must be
either "U", for upper triangular, and "L", for lower triangular.

`diag`

:Object of class `"character"`

. Must be
either `"U"`

, for unit triangular (diagonal is all ones), or
`"N"`

; see `triangularMatrix`

.

`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

`"ntrMatrix"`

extends class `"ngeMatrix"`

, directly, whereas

`"ntpMatrix"`

extends class `"ndenseMatrix"`

, directly.

Both extend Class `"triangularMatrix"`

, directly,
and class `"denseMatrix"`

, `"lMatrix"`

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="nsyMatrix")`

for details.

### See Also

Classes `ngeMatrix`

, `Matrix`

;
function `t`

### Examples

```
showClass("ntrMatrix")
str(new("ntpMatrix"))
(nutr <- as(upper.tri(matrix(, 4, 4)), "ndenseMatrix"))
str(nutp <- pack(nutr)) # packed matrix: only 10 = 4*(4+1)/2 entries
!nutp # the logical negation (is *not* logical triangular !)
## but this one is:
stopifnot(all.equal(nutp, pack(!!nutp)))
```

[Package

*Matrix* version 1.5-3

Index]