R: Triangular Sparse Compressed Row Matrices

dtRMatrix-class {Matrix} | R Documentation

## Triangular Sparse Compressed Row Matrices

### Description

The `dtRMatrix` class is a class of triangular, sparse matrices in the compressed, row-oriented format. In this implementation the non-zero elements in the rows are sorted into increasing columnd order.

### Objects from the Class

This class is currently still mostly unimplemented!

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. At present only the lower triangle form is allowed.

`diag`:

  Object of class `"character"`. Must be either `"U"`, for unit triangular (diagonal is all ones), or `"N"`; see `triangularMatrix`.

`j`:

  Object of class `"integer"` of length `nnzero(.)` (number of non-zero elements). These are the row numbers for each non-zero element in the matrix.

`p`:

  Object of class `"integer"` of pointers, one for each row, to the initial (zero-based) index of elements in the row. (Only present in the `dsRMatrix` class.)

`x`:

  Object of class `"numeric"` - the non-zero elements of the matrix.

`Dim`:

  The dimension (a length-2 `"integer"`)

`Dimnames`:

  corresponding names (or `NULL`), inherited from the `Matrix`, see there.

### Extends

Class `"dgRMatrix"`, directly. Class `"dsparseMatrix"`, by class `"dgRMatrix"`. Class `"dMatrix"`, by class `"dgRMatrix"`. Class `"sparseMatrix"`, by class `"dgRMatrix"`. Class `"Matrix"`, by class `"dgRMatrix"`.

### Methods

No methods currently with class "dsRMatrix" in the signature.

### See Also

Classes `dgCMatrix`, `dgTMatrix`, `dgeMatrix`

### Examples

    (m0 <- new("dtRMatrix"))
    (m2 <- new("dtRMatrix", Dim = c(2L,2L),
                            x = c(5, 1:2), p = c(0L,2:3), j= c(0:1,1L)))
    str(m2)
    (m3 <- as(Diagonal(2), "RsparseMatrix"))# --> dtRMatrix

[Package Matrix version 1.1-4 Index]