I've been writing some code to serialize and deserialize boost::numeric::ublas::matrixs. While writing unit tests for it I found out about the boost::numeric::ublas::equals function in matrix_assign.hpp. I was relieved, because I had previously been using a templated function to compare matrices. Unfortunately, it doesn't work for me with matrix<int>s. Consider the following cppunit test code: void testMatrixEqualsOperator() { using namespace boost::numeric::ublas; matrix<double> test; test.resize(3,3); CPPUNIT_ASSERT( equals(test,test) ); matrix<int> test1; test.resize(4,4); CPPUNIT_ASSERT( equals(test1,test1) ); } The first four lines work. Adding the next three lines causes the unit tests to fail with an Abort. This is not the standard way CppUnit records a failed test, it must be something failing inside the call to equals(). Previous messages referring to the equals() function argued that it wasn't ready for use because there was rarely a need to compare matrices in real applications. I would argue that it should be working as intended, if only to allow for proper unit testing of code that uses matrices. Here is the function I have been using instead. It works well for me with doubles and ints. Although, I imagine it is not particularly fast. E is for Element. template<class E> bool areMatricesEqual( boost::numeric::ublas::matrix<E> lhs, boost::numeric::ublas::matrix<E> rhs) { using boost::numeric::ublas; if (&lhs == &rhs) return true; if (lhs.size1() != rhs.size1()) return false; if (lhs.size2() != rhs.size2()) return false; typename matrix<E>::iterator1 l(lhs.begin1()); typename matrix<E>::iterator1 r(rhs.begin1()); while (l != lhs.end1()) { if (*l != *r) return false; ++l; ++r; } return true; } I am using gcc-3.3 on ubuntu-5.04 running on an AthlonXP. I'd be happy to provide any more info to help track down the bug. Assuming it is one. -- David Cameron University of British Columbia http://bar.psych.ubc.ca/People/Dave.html