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From "Jason Rennie" <jren...@gmail.com>
Subject Re: sparse matrix library
Date Wed, 30 Jan 2008 19:13:03 GMT
On Jan 30, 2008 1:58 PM, Ted Dunning <tdunning@veoh.com> wrote:

> Many of my matrices need both fast column AND fast row access.  They are
> also binary.  Yet another implementation.
>

Do you know a good storage format where both column and row access is
efficient?  Hadn't found a good one yet, but neither have I searched very
hard.  Also, do you have thoughts on sparse matrix construction?  I'm
actually using a separate "builder" class which gathers RCV triples, then
generates a matrix upon call to a build() function.  I don't modify a matrix
once built.  Certainly allows for efficient construction.  Though, I'm sure
we'd want sparse matrices to be mutable...

Personally, I'd prefer many optimized implementations to few inefficient
ones. :)  Do you have thoughts on an interface/abstract class?  Seems to me
we'd want a type parameter (generics) for function argument and return
types, even though everything would be handled with primitives
under-the-hood.

I imagine it won't be difficult to distribute basic matrix ops like
vector*matrix and matrix*matrix.  Are there specs/interfaces for the
map/reduce calls?

Jason

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