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c++eigen

What is the best way to care about assertion fail in Eigen C++?

I have a question what the best way is to care about assertion fail in Eigen C++. I know if there were wrong matrix calculation, Eigen stops program by assertion fail. For example,

MatrixXf a(2, 2);
MatrixXf b(1, 1);
MatrixXf c = a + b;

In this case, the size of matrix a and b is difference, so assertion fails occurs. Then what is the best way to avoid it ?

I can avoid, if I checked matrix size at every time before calculating. 

MatrixXf a(2, 2);
MatrixXf b(1, 1);
MatrixXf c;
if (a.cols() == b.cols() && a.rows() == b.rows()) {
    c = a + b;
}

But I think it's not smart way, checking each calculation.

Is there any better way to check it ? Could I catch exception by using try-catch ? Or does Eigen have any check function ?

Solution

  • You can predefine the eigen_assert macro to throw an exception instead of asserting. E.g.:

    #define eigen_assert(X) do { if(!(X)) throw std::runtime_error(#X); } while(false);
// make sure Eigen is not included before your define:
#include <Eigen/Core>

    But as @n.m. pointed out, you should rather fix your logic error, i.e., you should not try to add matrices if you are not sure that their sizes match.