Triangular Sparse Compressed Row Matrices

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"))
#> 0 x 0 sparse Matrix of class "dtRMatrix"
#> <0 x 0 matrix>
(m2 <- new("dtRMatrix", Dim = c(2L,2L),
                        x = c(5, 1:2), p = c(0L,2:3), j= c(0:1,1L)))
#> 2 x 2 sparse Matrix of class "dtRMatrix"
#>         
#> [1,] 5 1
#> [2,] . 2
str(m2)
#> Formal class 'dtRMatrix' [package "Matrix"] with 7 slots
#>   ..@ p       : int [1:3] 0 2 3
#>   ..@ j       : int [1:3] 0 1 1
#>   ..@ Dim     : int [1:2] 2 2
#>   ..@ Dimnames:List of 2
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>   ..@ x       : num [1:3] 5 1 2
#>   ..@ uplo    : chr "U"
#>   ..@ diag    : chr "N"
(m3 <- as(Diagonal(2), "RsparseMatrix"))# --> dtRMatrix
#> 2 x 2 sparse Matrix of class "dtRMatrix" (unitriangular)
#>         
#> [1,] I .
#> [2,] . I