dgCMatrix-class function

Compressed, sparse, column-oriented numeric matrices

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.

class

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")
• 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]