numpy (matrix solver) - python vs. matlab

Tue May 1 14:43:05 EDT 2012

On 04/30/2012 02:57 AM, Paul Rubin wrote:
> someone<newsboost at gmail.com> writes:
>>> A is not just close to singular: it's singular!
>> Ok. When do you define it to be singular, btw?
>> Singular means the determinant is zero, i.e. the rows or columns
> are not linearly independent. Let's give names to the three rows:
>> a = [1 2 3]; b = [11 12 13]; c = [21 22 23].
>> Then notice that c = 2*b - a. So c is linearly dependent on a and b.
> Geometrically this means the three vectors are in the same plane,
> so the matrix doesn't have an inverse.

Oh, thak you very much for a good explanation.
>>>> Which is the most accurate/best, even for such a bad matrix?
>> What are you trying to do? If you are trying to calculate stuff
> with matrices, you really should know some basic linear algebra.

Actually I know some... I just didn't think so much about, before 
writing the question this as I should, I know theres also something like 
singular value decomposition that I think can help solve otherwise 
illposed problems, although I'm not an expert like others in this forum, 
I know for sure :-)