Compressed, sparse, column-oriented numeric matrices

Description

The dgCMatrix class is a class of sparse numeric matrices in the compressed, sparse, column-oriented format. In this implementation the non-zero elements in the columns are sorted into increasing row order. dgCMatrix is the “standard” class for sparse numeric matrices in the Matrix package.

Objects from the Class

Objects can be created by calls of the form new("dgCMatrix", ...), more typically via as(*, "CsparseMatrix") or similar. Often however, more easily via Matrix(*, sparse = TRUE), or most efficiently via sparseMatrix().

Slots

x:

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

...

all other slots are inherited from the superclass "CsparseMatrix".

Methods

Matrix products (e.g., crossprod-methods), and (among other)

coerce

signature(from = "matrix", to = "dgCMatrix")

coerce

signature(from = "dgCMatrix", to = "matrix")

coerce

signature(from = "dgCMatrix", to = "dgTMatrix")

diag

signature(x = "dgCMatrix"): returns the diagonal of x

dim

signature(x = "dgCMatrix"): returns the dimensions of x

image

signature(x = "dgCMatrix"): plots an image of x using the levelplot function

solve

signature(a = "dgCMatrix", b = "..."): see solve-methods, notably the extra argument sparse.

lu

signature(x = "dgCMatrix"): computes the LU decomposition of a square dgCMatrix object

See Also

Classes dsCMatrix, dtCMatrix, lu

Examples

(m <- Matrix(c(0,0,2:0), 3,5))
str(m)
m[,1]