
Ublas : 
From: Georg Baum (georg.baum_at_[hidden])
Date: 20050709 15:01:07
Hello,
while playing a bit with the profiler I noticed that matrix_norm_inf
computes the norm by iterating over each element (i, j). The same is true
for matrix_norm_1 and matrix_norm_frobenius. This is of course
inefficient for sparse matrices.
I wonder why that is the case? I can't believe that such an inefficient
implementation is used without reason. Now I am wondering if I have to
expect more surprises like that? Or did I miss something?
I attach the patch I aam currently using for interested people to play
with. It to optimize the matrix norms and seems to work for
matrix_norm_inf (I did not yet test the other norms).
Georg