Matrix Norms

A =
  5 -5 -7
 -4  2 -4
 -7 -4  5
>> norm(A,'fro')
ans =
15
>> norm(A,inf)
ans =
17
>> norm(A,1)
ans=
16
>> norm(A)
ans =
12.0301
>> norm (A,2)
ans =  
12.0301

we observe that the 2-norm, the spectral norm, is the norm we get if we just ask for the norm. The smallest norm of the matrix is the spectral norm, it is the tightest measure.

Cem Ozdogan 2010-11-17