Matrix (version 0.99-3)

dCholCMatrix-class: Cholesky Decompositions of dsCMatrix Objects

Description

"dCholCMatrix" is class of Cholesky decompositions of symmetric, sparse, compressed, column-oriented matrices (the "dsCMatrix" class). "lCholCMatrix" is class showing the logical structure (positions of the non-zeros) of these Cholesky decompositions.

Objects from the Class

Objects can be created by calls of the form new("dCholCMatrix", ...) but are more commonly created from chol applied to dsCMatrix or lsCMatrix objects.

Extends

Class "dtCMatrix", directly. Class "dgCMatrix", by class "dtCMatrix".

Methods

No methods defined with class "dCholCMatrix" in the signature.

See Also

dgCMatrix-class

Examples

data(mm)
xpx <- crossprod(mm)
str(xpx)
str(ch <- chol(xpx))

## Visualize the sparseness:
dq <- function(ch) paste('"',ch,'"', sep="") ## dQuote(<UTF-8>) gives bad plots
image(xpx, main=paste("crossprod(mm) : Sparse", dq(class(xpx))))
image(ch, main= paste("chol (crossprod(mm)) : Sparse", dq(class(ch))))