[Numpy-tickets] [NumPy] #601: function for computing powers of a matrix
NumPy
numpy-tickets@scipy....
Thu Feb 14 15:34:25 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 stefan):
The approach used in numpy.matlib is a binary decomposition. If the SVD
can't be used for some reason, it would be useful to have this exposed to
numpy in general.
The equivalent code looks something like:
{{{
def mpower(A,n):
B = A
p = int(np.floor(np.log(n)/np.log(2))) # 2^? is n
for i in range(p):
B = np.dot(B,B)
for i in range(n-2**p):
B = np.dot(B,A)
return B
}}}
See defmatrix.py:215.
--
Ticket URL: <http://scipy.org/scipy/numpy/ticket/601#comment:6>
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