R help - Aug 2012 - reshape cast to a sparse matrix?

I am using the reshape package to convert a series of values into a binary
matrix. The binary matrix is very sparse with many zeros and I'd like to
use cast to generate a sparse matrix using any of the sparse matrix
packages of choice. Is there functionality to support this use?

Are there strategies or other packages that that may be useful?

Due to memory constraints, it would be best to convert to sparse matrix on
the fly rather than build the full matrix and then convert it.

Thanks for the help,
Yin

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>>>>> Yin Aphinyanaphongs <yinnerspace at gmail.com>
>>>>>     on Tue, 14 Aug 2012 09:13:21 -0400 writes:
    > I am using the reshape package to convert a series of
    > values into a binary matrix. The binary matrix is very
    > sparse with many zeros and I'd like to use cast to
    > generate a sparse matrix using any of the sparse matrix
    > packages of choice. Is there functionality to support this
    > use?

Well, the Matrix package (part of every R) has several
convenient ways to construct sparse matrices,
depending on their (special) structure.

We mostly advertize   sparseMatrix()   which has
a large 'Examples' section.

If you want, you can contact me offline for more help,
but you'd definitely have to provide more details, and a
selfcontained example.

Martin Maechler, ETH Zurich,
one of the two 'Matrix' authors.

    > Are there strategies or other packages that that may be
    > useful?

    > Due to memory constraints, it would be best to convert to
    > sparse matrix on the fly rather than build the full matrix
    > and then convert it.

    > Thanks for the help, Yin