[Scipy-tickets] [SciPy] #1859: Sparse matrix subtraction with another matrix seems to regard the other matrix as a scalar
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scipy-tickets@scipy....
Fri Mar 1 21:00:37 CST 2013
#1859: Sparse matrix subtraction with another matrix seems to regard the other
matrix as a scalar
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Reporter: photon.engine | Owner: jakevdp
Type: defect | Status: new
Priority: normal | Milestone: Unscheduled
Component: scipy.sparse | Version: 0.10.1
Keywords: sparse scalar subtract |
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Comment(by photon.engine):
I'll try .dot() on my code, thanks for the suggestion.
I must admit I'm new to this SciPy business (worked with NumPy for some
time), so I'm not sure how CSR and DIA matrices differ. I tried to
reproduce your results with
{{{
import numpy
import scipy.sparse
c = scipy.sparse.csr_matrix([[1,0,0],[2,3,0],[0,0,4]])
d = scipy.sparse.dia_matrix([[1,0,0],[2,3,0],[0,0,4]])
x = numpy.array([10, 20, 30])
print(c.toarray())
print(d.toarray())
print(numpy.dot(c, x).shape, numpy.dot(c, x).dtype)
print(c.dot(x))
print(numpy.dot(d, x).shape, numpy.dot(d, x).dtype)
print(d.dot(x))
}}}
and I got
{{{
[[1 0 0]
[2 3 0]
[0 0 4]]
[[1 0 0]
[2 3 0]
[0 0 4]]
(3,) object
[ 10 80 120]
(3,) object
[ 10 80 120]
}}}
So the only difference is that, on my computer, CSR doesn't crash.
However, it still doesn't quite explain why I received the particular
error message about scalars...
--
Ticket URL: <http://projects.scipy.org/scipy/ticket/1859#comment:2>
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