[SciPy-user] cholesky decomposition fails
Chris Fonnesbeck
fonnesbeck at gmail.com
Mon Oct 31 09:20:49 EST 2005
I am trying to change over some of my kalman filtering code over to
the new scipy, and have run into a failure in the cholesky
decomposition function in scipy.linalg:
from scipy.linalg import cholesky
from scipy import array
# Very simple decomposition
cholesky(array([[1,0],[0,1]]))
Using ipython for more debugging information, I get:
---------------------------------------------------------------------------
exceptions.ValueError Traceback (most
recent call last)
/Users/chris/<console>
/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/scipy/linalg/decomp.py
in cholesky(a=array([[ 1., 0.],
[ 0., 1.]]), lower=0, overwrite_a=0)
317
318 """
--> 319 a1 = asarray_chkfinite(a)
a1 = undefined
global asarray_chkfinite = <function asarray_chkfinite at 0x48d570>
a = array([[ 1., 0.],
[ 0., 1.]])
320 if len(a1.shape) != 2 or a1.shape[0] != a1.shape[1]:
321 raise ValueError, 'expected square matrix'
/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/scipy_base/function_base.py
in asarray_chkfinite(x=array([[ 1., 0.],
[ 0., 1.]]))
24 """Like asarray except it checks to be sure no NaNs or
Infs are present.
25 """
---> 26 x = asarray(x)
x = array([[ 1., 0.],
[ 0., 1.]])
global asarray = <function asarray at 0x47de70>
27 if not all(_nx.isfinite(x)):
28 raise ValueError, "Array must not contain infs or nans."
/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/scipy_base/type_check.py
in asarray(a=array([[ 1., 0.],
[ 0., 1.]]), typecode=None, savespace=None)
48 r.savespace(savespace)
49 return r
---> 50 return array(a,typecode,copy=0,savespace=savespace or 0)
global array = <built-in function array>
a = array([[ 1., 0.],
[ 0., 1.]])
typecode = None
global copy = undefined
savespace = None
51
52 def asfarray(a, typecode=None, savespace=None):
ValueError: Invalid type for array
Clearly, my array does not contain inf's or nan's.
C.
--
Chris Fonnesbeck
Atlanta, GA
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