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From: (noreply_at_[hidden])
Date: 2006-07-25 01:54:16

Bugs item #1528178, was opened at 2006-07-25 05:54
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Category: None
Group: None
Status: Open
Resolution: None
Priority: 9
Submitted By: Matthias Troyer (troyer)
Assigned to: Nobody/Anonymous (nobody)
Summary: ublas: bug in mapped_vector_of_mapped_vector

Initial Comment:
There is a serious bug in the mapped_vector_of_mapped_vector spare
matrix type. Rows containing only zero elements are not treated
correctly in prod(). The following code should give a vector that
contains only 1 in the last element. Instead prod() gives a vector
containing 1 in each element. In debug mode this bug is found by the

Check failed in file boost/boost/numeric/ublas/detail/
vector_assign.hpp at line 371:
detail::expression_type_check (v, cv)

The bug appears in Boost 1.33 as well as in the CVS version

#include <boost/numeric/ublas/matrix_sparse.hpp>
#include <boost/numeric/ublas/vector.hpp>

int main()
   boost::numeric::ublas::vector<double> v(64);
   boost::numeric::ublas::vector<double> w(64);
   v[63] = 1.;
   m(63,63) = 1.;
   w = boost::numeric::ublas::prod(m,v);


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