LU-class {Matrix} | R Documentation |
The "LU"
class is the class of LU decompositions of
real matrices.
Objects can be created by calls of the form new("LU", ...)
.
More commonly the objects are created explicitly from calls of the form
lu(mm)
where mm
is an object that inherits from the
"dgeMatrix"
class or as a side-effect of other functions applied
to "dgeMatrix"
objects.
x
:"numeric"
. The "L"
(unit lower triangular) and "U"
(upper triangular) factors
of the original matrix. These are stored in a packed format
described in the Lapack manual.Dim
:"integer"
- the dimensions
of the original matrix - must be an integer vector with exactly two
non-negative values.pivot
:"integer"
- a vector of
length min(Dim)
that describes the permutation applied to
the rows of the original matrix. The contents of this vector are
described in the Lapack manual.signature(x = "LU")
: Produce the "L"
and
"U"
factors as a named list of matrices.
class dgeMatrix
and functions lu
,
expand
.
mm <- Matrix(round(rnorm(9),2), nrow = 3, ncol = 3) mm str(lum <- lu(mm)) elu <- expand(lum) elu elu$L %*% elu$U