R: Transformation to other sparse formats

foreign {spam} | R Documentation

## 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`.

### 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`.

### Value

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

### Author(s)

Reinhard Furrer

### See Also

`triplet`, `Matrix` or `matrix.csr`

### Examples

    ## 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.

    ## End(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)

    ## End(Not run)

    ## Not run:
    # a dataset contained in Matrix
    data(KNex)
    as.spam.dgCMatrix(KNex$mm)

    ## End(Not run)

[Package spam version 2.2-2 Index]