spam (version 2.5-1)

foreign: Transformation to other sparse formats

Description

Transform between the spam sparse format to the matrix.csr format of SparseM and dgRMatrix format of Matrix

Usage

as.spam.matrix.csr(x)
as.dgRMatrix.spam(x)
as.dgCMatrix.spam(x)
as.spam.dgRMatrix(x)
as.spam.dgCMatrix(x)

Arguments

x

sparse matrix of class spam, matrix.csr, dgRMatrix or dgCMatrix.

Value

According to the call, a sparse matrix of class spam, matrix.csr, dgRMatrix or dgCMatrix.

Details

We do not provide any S4 methods and because of the existing mechanism a standard S3 does not work.

The functions are based on require.

Notice that as.matrix.csr.spam should read as as."matrix.csr".spam.

See Also

triplet, Matrix or matrix.csr

Examples

# NOT RUN {
# }
# NOT RUN {
S <- diag.spam(4)
R <- as.dgRMatrix.spam( S) 
C <- as.dgCMatrix.spam( S)
as.spam.dgCMatrix(C) 
slotNames(U)
slotNames(R)
# For column oriented sparse formats a transpose does not the job,
# as the slot names change.


# as.spam(R) does not work.
# }
# NOT RUN {
# }
# NOT RUN {
# for transformations between SparseM and spam:
as.matrix.csr.spam <- function(x,...) {
    newx <- new("matrix.csr")
    slot(newx,"ra",check=FALSE) <- x@entries
    slot(newx,"ja",check=FALSE) <- x@colindices
    slot(newx,"ia",check=FALSE) <- x@rowpointers
    slot(newx,"dimension",check=FALSE) <- x@dimension
    return(newx)
  }       
U <- as.matrix.csr.spam( S) 
# }
# NOT RUN {
# }
# NOT RUN {
# a dataset contained in Matrix
data(KNex)
as.spam.dgCMatrix(KNex$mm) 

# }