Message-ID: <878vabregr.fsf@gnu.org>
Date: 2012-11-08T21:07:16Z
From: Sam Steingold
Subject: LiblineaR: accept sparse matrices
In-Reply-To: <loom.20121107T224930-40@post.gmane.org> (Ben Bolker's message of "Wed, 7 Nov 2012 21:51:07 +0000")
> * Ben Bolker <oobyxre at tznvy.pbz> [2012-11-07 21:51:07 +0000]:
>
> Sam Steingold <sds <at> gnu.org> writes:
>
>> 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)?
It was CCed (not BCCed) to Thibault Helleputte <thelleputte at gmail.com>
> 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 ...
The library in question is merely a thin layes which passes the data to
the underlying C++ library. The original library comes with a command
line interface which accepts input file in sparse matrix format _ONLY_.
--
Sam Steingold (http://sds.podval.org/) on Ubuntu 12.04 (precise) X 11.0.11103000
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