Hi,

A while back there was some code posted for doing logical operations on matrices, but I can't get it to work on eigen 3.1.2 on OSX 10.7.5:

test.cpp:

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#include <Eigen/Core>
#include <Eigen/Dense>
#include <Eigen/Eigen>

using namespace Eigen;

void test()
{
   MatrixXf X(10, 10);
   Matrix<bool,Dynamic,Dynamic> Y = X > 40;
}

Compilation fails:

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$ /usr/local/bin/g++-4.7 -I/usr/local/include/eigen3 -c test.cpp -o test.otest.cpp: In function 'void test()':
test.cpp:10:41: error: no match for 'operator>' in 'X > 40'

Any ideas?
Thanks.

These coefficient-wise operators only work on arrays, not matrices. You can get an array view using the array() method:

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MatrixXf X(10, 10);
Array<bool, Dynamic, Dynamic> Y = X.array() > 40;


For a list of all supported opeators, see http://eigen.tuxfamily.org/dox/QuickRefPage.html#QuickRef_Coeffwise

thanks!