Matrix (version 1.7-6)

dsCMatrix-class: Numeric Symmetric Sparse (column compressed) Matrices

Description

The dsCMatrix class is a class of symmetric, sparse numeric matrices in the compressed, column-oriented format. In this implementation the non-zero elements in the columns are sorted into increasing row order.

The dsTMatrix class is the class of symmetric, sparse numeric matrices in triplet format.

See Also

Classes dgCMatrix, dgTMatrix, dgeMatrix and those mentioned above.

Examples

 
library(utils, pos = "package:base", verbose = FALSE)

mm <- Matrix(toeplitz(c(10, 0, 1, 0, 3)), sparse = TRUE)
mm # automatically dsCMatrix
str(mm)
mT <- as(as(mm, "generalMatrix"), "TsparseMatrix")

## Either
(symM <- as(mT, "symmetricMatrix")) # dsT
(symC <- as(symM, "CsparseMatrix")) # dsC
## or
sT <- Matrix(mT, sparse=TRUE, forceCheck=TRUE) # dsT

sym2 <- as(symC, "TsparseMatrix")
## --> the same as 'symM', a "dsTMatrix"
# \dontshow{
stopifnot(identical(sT, symM), identical(sym2, symM),
          class(sym2) == "dsTMatrix",
	  identical(sym2[1,], sT[1,]),
	  identical(sym2[,2], sT[,2]))
# }