R help - Nov 2012 - LiblineaR: accept sparse matrices

Thibault,

It would be nice if LiblineaR() accepted data in the form of a sparse
matrix (it does not accept whatever e1071::read.matrix.csr returns).

It would also be nice if there were functions to read/write files in the
native liblinear file format; I am sure the original liblinear library
provides at least the input code.

Thanks!

-- 
Sam Steingold (http://sds.podval.org/) on Ubuntu 12.04 (precise) X 11.0.11103000
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Sam Steingold <sds <at> gnu.org> writes:
> 
> Thibault,
> 
> It would be nice if LiblineaR() accepted data in the form of a sparse
> matrix (it does not accept whatever e1071::read.matrix.csr returns).
> 
> It would also be nice if there were functions to read/write files in the
> native liblinear file format; I am sure the original liblinear library
> provides at least the input code.
  You appear to have sent this to the general R-help mailing list
rather than to the maintainer (or maybe you Bcc'd the maintainer)?

  Sparse matrices are nice, but once you start using sparse matrices
you have to start worrying about the details of which linear algebra
operators have been defined for them (e.g. whether the available operators
allow pivoting, or work on rank-deficient matrices, or ...)  So it's
not always as easy as flipping a switch ...