[Numpy-tickets] [NumPy] #601: function for computing powers of a matrix
NumPy
numpy-tickets@scipy....
Sun Feb 24 18:36:15 CST 2008
#601: function for computing powers of a matrix
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Reporter: LevGivon | Owner: somebody
Type: enhancement | Status: new
Priority: normal | Milestone: 1.0.5
Component: numpy.linalg | Version: devel
Severity: normal | Resolution:
Keywords: |
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Comment (by charris):
Powers can be defined for normal matrices, i.e., matrices for which
A*transpose(A) = transpose(A)*A, but normality itself is subject to
numerical fuzziness in computational practice. And for normal matrices you
still need to deal with square roots of negative reals and the fact that
there can be a multiplicity of roots, and so on and so forth. I think the
user needs to know what sort of matrices they are dealing with and what
they intend before they use a function like this.
This functionality could be part of a package, perhaps in a package for
symmetric positive indefinite matrices; those matrices are like the non-
negative reals. But I don't think numpy should try to implement such a
specialized function.
However, raising matrices to (small) non-negative integer powers is
possible and might cover most needs. A special integer power function
might do the trick.
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Ticket URL: <http://scipy.org/scipy/numpy/ticket/601#comment:7>
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