[Scipy-tickets] [SciPy] #1525: linalg.eig does not normalize eigenvectors
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Tue Sep 27 10:21:07 CDT 2011
#1525: linalg.eig does not normalize eigenvectors
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Reporter: blackhorizon | Owner: somebody
Type: defect | Status: new
Priority: normal | Milestone: Unscheduled
Component: scipy.linalg | Version: 0.8.0
Keywords: eigenvectors normalization |
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scipy.linalg.eig does not seem to normalize the eigenvectors when it is
solving a generalized eigenvalue problem, while the documentation
indicates that the vectors should be normalized.
On an ordinary eigenvalue problem the vectors do seem to be normalized.
From the documentation : "The normalized right eigenvector corresponding
to the eigenvalue w[i] is the column vr[:,i]."
currently experiencing this problem with scipy 0.8.0, under ubuntu linux
11.04 (natty narwhal)
I did not test this with other versions.
code to reproduce the problem :
{{{
import numpy,scipy
M1 = numpy.random.uniform(size=(100,100))
M2 = numpy.random.uniform(size=(100,100))
D,Z = scipy.linalg.eig(M1,M2)
print numpy.linalg.norm(Z[:,0])
}}}
If the vectors are normalized, the print-statement should print 1.0, but
instead it produces values that are generally between 3 and 5.
--
Ticket URL: <http://projects.scipy.org/scipy/ticket/1525>
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