dCholCMatrix-class {Matrix} | R Documentation |
The class of Cholesky decompositions of symmetric, sparse
compressed column matrices from the "dsCMatrix"
class.
Objects can be created by calls of the form new("dCholCMatrix", ...)
but are more commonly created from chol
applied to an
dsCMatrix
object.
perm
:"integer"
giving the
permutation of the rows and columns chosen to minimize fill-in.
If pivoting has not been applied this will be an integer vector of
length 0.diag
:"dtCMatrix"
class. It is always "N"
for this class.uplo
:"U"
or "u"
) or the lower triangle
("L"
or "l"
) is stored. At present only the lower
triangle form is allowed.p
:"integer"
of pointers, one
for each column, to the initial (zero-based) index of elements in
the column.i
:"integer"
of length nnzero
(number of non-zero elements). These are the row numbers for
each non-zero element in the matrix.x
:"numeric"
- the non-zero
elements of the matrix.factors
:"list"
- a list
of factorizations of the matrix. Dim
:"integer"
- the dimensions
of the matrix - must be an integer vector with exactly two
non-negative values.Dimnames
:"Matrix"
class, see Matrix-class
.D
:"numeric"
- the diagonal
elements of the matrix D in the LDL' decomposition.Parent
:"integer"
- the
elimination tree of the (possibly permuted) symmetric matrix.
Class "dtCMatrix"
, directly.
Class "dgCMatrix"
, by class "dtCMatrix"
.
No methods defined with class "dCholCMatrix" in the signature.
data(mm) xpx <- crossprod(mm) str(xpx) str(ch <- chol(xpx)) ## Visualize the sparseness: image(xpx, main=paste("crossprod(mm) : Sparse",dQuote(class(xpx)))) image(ch, main=paste("chol (crossprod(mm)) : Sparse", dQuote(class(ch))))