Re: [Lib2geom-devel] [Inkscape-devel] Help with numpy.linalg.solve

[Nathan H. <nj...@nj...>]

On Fri, Apr 11, 2014 at 12:34:38PM +0100, Alex Valavanis wrote:
> Armadillo supports eigenvalue searches in sparse matrices (although you can
> only get selected eigenvalues) but doesn't support sparse matrix inversions
> yet.

I don't think anyone does sparse exact inversion - too much infill.
It's an interesting question what eps approximate sparse inverses
there are, the rank-k inverse made using the sparse svd algorithms
would be the L2 solution (USV -> V^T (1/S) U^T).  But there are
possibly better choices (e.g. L1).  I don't know if there are any
eps inverses which are not outer products.

(yes, for 3x3 a dense inverse is fine.)

njh