# ltrMatrix-class: Triangular Dense Logical Matrices In Matrix: Sparse and Dense Matrix Classes and Methods

 ltrMatrix-class R Documentation

## Triangular Dense Logical Matrices

### Description

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

Both extend classes `"ldenseMatrix"` and `"triangularMatrix"`, directly; further, class `"Matrix"`, `"lMatrix"` and others, indirectly. Use `showClass("ltrMatrix")`, e.g., for details.

### Methods

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

Classes `lgeMatrix`, `Matrix`; function `t`

### Examples

```showClass("ltrMatrix")

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

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