[Numpy-discussion] Sparse matrices in NumPy?
Charles G Waldman
cgw at fnal.gov
Mon Jun 5 12:22:20 CDT 2000
Paul Gettings writes:
> > > However, the matrix is empty except for the main diagonal.
> > Multiplying by a diagonalized matrix is just vectorized multiplication:
> > a 0 0
> > 0 b 0 . <x, y, z> = <az, by, cz>
> > 0 0 c
> My mistake - I need to multiply the 7731x7731 by a 7731x220 element matrix -
> square matrix times rectangular matrix, not just 2 diagonal matrices.
> Otherwise, the problem wouldn't be so hard. :)
Still it's not so bad, you just need to break the 7731x220 matrix into
220 vectors of length 7731 and multiply each of them by the diagonal
"matrix", one at a time, and glue the results back together. The
7731x220 matrix should weigh in at about 6MB, hopefully you have
enough memory for this...
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