From: Charles G W. <cg...@fn...> - 2000-06-05 17:24:14
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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... |