[Numpy-discussion] Inversion of near singular matrices.

Charles R Harris charlesr.harris at gmail.com
Sun Jan 30 00:35:15 EST 2011

On Sat, Jan 29, 2011 at 10:11 PM, Algis Kabaila <akabaila at pcug.org.au>wrote:

> On Sunday 30 January 2011 09:10:30 Sturla Molden wrote:
> > Den 29.01.2011 12:40, skrev Algis Kabaila:
> > > So my question is: how can one reliably detect singularity
> > > (or near singularity) and raise an exception?
> >
> > Use an SVD, examine the singular values.
> I gather that SVD is the Singular Value Decomposition, but I
> have no idea how to perform such decomposition. Would you care
> to refer me to some simple source material?  I have been advised
> to watch the condition numbers. No doubt, SVD and condition
> numbers are related.  The references about condition numbers are
> very interesting and I intend to follow them in the first
> instance.
Use numpy.linalg.svd. The condition number is the ratio of the largest
singular value to the smallest.


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