dsCMatrix-class {Matrix}R Documentation

Symmetric, compressed, sparse column matrices

Description

The dsCMatrix class is a class of symmetric, sparse matrices in the compressed, column-oriented format. In this implementation the non-zero elements in the columns are sorted into increasing row order. The dsTMatrix class is a class of symmetric, sparse matrices in triplet format.

Objects from the Class

Objects can be created by calls of the form new("dsCMatrix", ...) or new("dsTMatrix", ...)

Slots

uplo:
A character object indicating if the upper triangle ("U" or "u") or the lower triangle ("L" or "l") is stored. At present only the lower triangle form is allowed.
p:
Object of class "integer" of pointers, one for each column, to the initial (zero-based) index of elements in the column. (Only present in the dsCMatrix class.)
i:
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.
j:
Object of class "integer" of length nnzero (number of non-zero elements). These are the column numbers for each non-zero element in the matrix. (Only present in the dsTMatrix class.)
x:
Object of class "numeric" - the non-zero elements of the matrix.
factors:
Object of class "list" - a list of factorizations of the matrix.
Dim:
Object of class "integer" - the dimensions of the matrix - must be an integer vector with exactly two non-negative values.

Extends

Class "dgCMatrix", directly.

Methods

solve
signature(a = "dsCMatrix", b = "matrix"): Solve a linear system of equations defined by x using a Cholesky decomposition.
chol
signature(x = "dsCMatrix", pivot = "logical"): Returns (and stores) the Cholesky decomposition of the matrix x. If pivot is TRUE (the default) Metis is used to create a reordering of the rows and columns of x so as to minimize fill-in.
determinant
signature(x = "dsCMatrix", logarithm = "missing"): Evaluate the determinant of x on the logarithm scale. This creates and stores the Cholesky factorization.
determinant
signature(x = "dsCMatrix", logarithm = "logical"): Evaluate the determinant of x on the logarithm scale or not, according to the logarithm argument. This creates and stores the Cholesky factorization.
t
signature(x = "dsCMatrix"): Transpose. Because x is symmetric this has no effect.
t
signature(x = "dsTMatrix"): Transpose. For the dsTMatrix class the row and column indices are interchanged so that a matrix for which the upper triangle is stored produces a matrix for which the lower triangle is stored and vice versa.
coerce
signature(from = "dsCMatrix", to = "dgTMatrix")
coerce
signature(from = "dsCMatrix", to = "dgeMatrix")
coerce
signature(from = "dsCMatrix", to = "matrix")
coerce
signature(from = "dsTMatrix", to = "dgeMatrix")
coerce
signature(from = "dsTMatrix", to = "dsCMatrix")
coerce
signature(from = "dsTMatrix", to = "dsyMatrix")
coerce
signature(from = "dsTMatrix", to = "matrix")

See Also

dgCMatrix-class, dgTMatrix-class, dgeMatrix-class


[Package Matrix version 0.95-10 Index]