[Numpy-discussion] numarray.linear_algrebra > cholesky_decomposition problem

[Todd Miller]

It's a bug in the recent port of mlab.py.  Numarray doesn't really
support spacesaver, and it doesn't fake it yet either.  I removed
the spacesaver code for numarray-0.7.

On Fri, 2003-08-29 at 04:04, Justin Worrall wrote:
> Hi, 
> 
> I'm having problems using the cholesky decomposition function -
> perhaps someone could point out where I am going wrong. Many thanks, 
> 
> Justin 
> 
> dingy /ms/user/w/worrall 22$ python 
> Python 2.3 (#1, Aug 19 2003, 16:53:06) 
> [GCC 2.95.2 19991024 (release)] on sunos5 
> Type "help", "copyright", "credits" or "license" for more information.
> >>> from numarray import * 
> >>> from numarray.linear_algebra import * 
> >>> x=array([[1.0,0.0],[0.5,1.0]]) 
> >>> x 
> array([[ 1. ,  0. ], 
>        [ 0.5,  1. ]]) 
> >>> cholesky_decomposition(x) 
> Traceback (most recent call last): 
>   File "<stdin>", line 1, in ? 
>   File
> "/u/worrall/Python-2.3/numarray/linear_algebra/LinearAlgebra2.py",
> line 159, in cholesky_decomposition 
>     return copy.copy(num.transpose(mlab.triu(a,k=0))) 
>   File "/u/worrall/Python-2.3/numarray/linear_algebra/mlab.py", line
> 134, in triu 
>     svsp = m.spacesaver() 
> AttributeError: 'NumArray' object has no attribute 'spacesaver' 
> >>> 
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-- 
Todd Miller <jmiller at stsci.edu>