[Scipy-tickets] [SciPy] #316: adding sparse matrices sometimes gives wrong result
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Tue Dec 5 14:35:28 CST 2006
#316: adding sparse matrices sometimes gives wrong result
---------------------------------+------------------------------------------
Reporter: martin_wiechert | Owner: somebody
Type: defect | Status: new
Priority: normal | Milestone:
Component: scipy.sparse | Version: devel
Severity: critical | Resolution:
Keywords: sparse, wrong value |
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Comment (by edschofield):
Yes, Robert, good point. cscadd and most of the other Fortran functions
require sorted row/column indices. If we sort the indices manually after
{{{
>>> a[3, 0] = -1
}}}
by swapping the first two elements of a.data and a.rowind, the addition
works correctly.
So the problem is that the cscsetel function isn't sorting the rows
correctly...
--
Ticket URL: <http://projects.scipy.org/scipy/scipy/ticket/316#comment:3>
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