CHMfactor-class {Matrix}R Documentation

CHOLMOD-based Cholesky Factorizations

Description

The virtual class "CHMfactor" is a class of CHOLMOD-based Cholesky factorizations of symmetric, sparse, compressed, column-oriented matrices. Such a factorization is simplicial (virtual class "CHMsimpl") or supernodal (virtual class "CHMsuper"). Objects that inherit from these classes are either numeric factorizations (classes "dCHMsimpl" and "dCHMsuper") or symbolic factorizations (classes "nCHMsimpl" and "nCHMsuper").

Objects from the Class

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

Slots

of "CHMfactor" and all classes inheriting from it:

perm:
An integer vector giving the 0-based permutation of the rows and columns chosen to reduce fill-in and for post-ordering.
colcount:
Object of class "integer" ....
type:
Object of class "integer" ....

Slots of the non virtual classes “[dl]CHM(super|simpl)”:

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 classes that contain "CHMsimpl".
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. Only present in classes that contain "CHMsimpl".
x:
For the "d*" classes: "numeric" - the non-zero elements of the matrix.

Methods

coerce
signature(from = "CHMfactor", to = "sparseMatrix")
image
signature(x = "CHMfactor")
solve
signature(a = "CHMfactor", b = "ddenseMatrix") The solve methods for a "CHMfactor" object take an optional third argument system whose value can be one of the character strings "A", "LDLt", "LD", "DLt", "L", "Lt", "D", "P" or "Pt". This argument describes the system to be solved. The default is to solve Ax = b for x where A is sparse, positive-definite matrix that was factored to produce "a".
solve
signature(a = "CHMfactor", b = "dsparseMatrix")
solve
signature(a = "CHMfactor", b = "matrix")

See Also

Cholesky, also for examples; class dgCMatrix.


[Package Matrix version 0.999375-4 Index]