R: Triangular, dense, numeric matrices

dtrMatrix-class {Matrix} | R Documentation

## Triangular, dense, numeric matrices

### Description

The `"dtrMatrix"` class is the class of triangular, dense, numeric matrices in nonpacked storage. The `"dtpMatrix"` class is the same except in packed storage.

### Objects from the Class

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

### Slots

`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`.

`x`:

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

`Dim`:

  Object of class `"integer"`. The dimensions of the matrix which must be a two-element vector of non-negative integers.

### Extends

Class `"ddenseMatrix"`, directly. Class `"triangularMatrix"`, directly. Class `"Matrix"` and others, by class `"ddenseMatrix"`.

### Methods

%*%

  `signature(x = "dtrMatrix", y = "matrix")` and other signatures (use `showMethods("%*%", class="dtrMatrix")`): matrix multiplication. Multiplication of (matching) triangular matrices now should remain triangular (in the sense of class triangularMatrix).

crossprod,tcrossprod

  `signature(x = "dtrMatrix", y = "matrix")` and other signatures, see `"%*%"` above.

coerce

  `signature(from = "dgeMatrix", to = "dtrMatrix")`

coerce

  `signature(from = "dtrMatrix", to = "matrix")`

coerce

  `signature(from = "dtrMatrix", to = "ltrMatrix")`

coerce

  `signature(from = "dtrMatrix", to = "matrix")`

coerce

  `signature(from = "matrix", to = "dtrMatrix")`

norm

  `signature(x = "dtrMatrix", type = "character")`

rcond

  `signature(x = "dtrMatrix", norm = "character")`

solve

  `signature(a = "dtrMatrix", b = "missing")`

solve

  `signature(a = "dtrMatrix", b = "matrix")`

### See Also

Classes `ddenseMatrix`, `dtpMatrix`, `triangularMatrix`

### Examples

    (m <- rbind(2:3, 0:-1))
    (M <- as(m, "dgeMatrix"))

    (T <- as(M, "dtrMatrix")) ## upper triangular is default
    (T2 <- as(t(M), "dtrMatrix"))
    stopifnot(T@uplo == "U", T2@uplo == "L", identical(T2, t(T)))

[Package Matrix version 1.0-6 Index]