Status: New
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Labels: Type-Defect Priority-Medium

New issue 2225 by [email protected]: Enhancing Matrix Norm
http://code.google.com/p/sympy/issues/detail?id=2225

Currently the norm function on matrices only works for rows or columns (1d matrices) and only performs the 2-norm
norm(x) = sqrt(Sum_i (x[i])**2))

I think it would be nice to have Sympy's norm function identically to numpy's linalg.norm. This can be done without breaking backwards compatibility.

help numpy.linalg.norm yields:

...
The following norms can be calculated:

=====  ============================  ==========================
ord    norm for matrices             norm for vectors
=====  ============================  ==========================
None   Frobenius norm                2-norm
'fro'  Frobenius norm                --
inf    max(sum(abs(x), axis=1))      max(abs(x))
-inf   min(sum(abs(x), axis=1))      min(abs(x))
1      max(sum(abs(x), axis=0))      as below
-1     min(sum(abs(x), axis=0))      as below
2      2-norm (largest sing. value)  as below
-2     smallest singular value       as below
other  --                            sum(abs(x)**ord)**(1./ord)
=====  ============================  ==========================

Thoughts? Concerns?

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