R: Read and Write Sparse Matrix Format Files

foreign {slam} | R Documentation

## Read and Write Sparse Matrix Format Files

### Description

Read and write CLUTO sparse matrix format files, or the CCS format variant employed by the MC toolkit.

### Usage

    read_stm_CLUTO(file)
    write_stm_CLUTO(x, file)
    read_stm_MC(file, scalingtype = NULL)
    write_stm_MC(x, file)

### Arguments

`file` | a character string with the name of the file to read or write.
`x` | a matrix object.
`scalingtype` | a character string specifying the type of scaling to be used, or `NULL` (default), in which case the scaling will be inferred from the names of the files with non-zero entries found (see Details).

### Details

Documentation for CLUTO including its sparse matrix format is available from http://www-users.cs.umn.edu/~karypis/cluto/.

`read_stm_CLUTO` reads CLUTO sparse matrices, returning a simple triplet matrix.

`write_stm_CLUTO` writes CLUTO sparse matrices. Argument `x` must be coercible to a simple triplet matrix via `as.simple_triplet_matrix`.

MC is a toolkit for creating vector models from text documents (see http://www.cs.utexas.edu/users/dml/software/mc/). It employs a variant of Compressed Column Storage (CCS) sparse matrix format, writing data into several files with suitable names: e.g., a file with ‘_dim’ appended to the base file name stores the matrix dimensions. The non-zero entries are stored in a file the name of which indicates the scaling type used: e.g., ‘_tfx_nz’ indicates scaling by term frequency (t), inverse document frequency (f) and no normalization (x). See ‘README’ in the MC sources for more information.

`read_stm_MC` reads such sparse matrix information with argument `file` giving the path with the base file name, and returns a simple triplet matrix.

`write_stm_MC` writes matrices in MC CCS sparse matrix format. Argument `x` must be coercible to a simple triplet matrix via `as.simple_triplet_matrix`.

[Package slam version 0.1-40 Index]