| ddiMatrix-class {Matrix} | R Documentation |
The class "ddiMatrix" of numerical diagonal matrices.
Note that diagonal matrices now extend sparseMatrix, whereas
they did extend dense matrices earlier.
Objects can be created by calls of the form new("ddiMatrix", ...)
but typically rather via Diagonal.
x:numeric vector. For an n * n
matrix, the x slot is of length n or 0,
depending on the diag slot:
diag:"character" string, either "U" or
"N" where "U" denotes unit-diagonal, i.e., identity
matrices.
Dim,Dimnames:matrix dimension and
dimnames, see the Matrix class
description.
Class "diagonalMatrix", directly.
Class "dMatrix", directly.
Class "sparseMatrix", indirectly, see
showClass("ddiMatrix").
signature(x = "ddiMatrix", y = "ddiMatrix"): ...
Class diagonalMatrix and function Diagonal.
(d2 <- Diagonal(x = c(10,1)))
str(d2)
## slightly larger in internal size:
str(as(d2, "sparseMatrix"))
M <- Matrix(cbind(1,2:4))
M %*% d2 #> `fast' multiplication
chol(d2) # trivial
stopifnot(is(cd2 <- chol(d2), "ddiMatrix"),
all.equal(cd2@x, c(sqrt(10),1)))