doc/snippets/PartialRedux_count.cpp - eigen - Git at Google

 Matrix3d m = Matrix3d::Random();
 cout << "Here is the matrix m:" << endl << m << endl;
 Matrix<ptrdiff_t, 3, 1> res = (m.array() >= 0.5).rowwise().count();
 cout << "Here is the count of elements larger or equal than 0.5 of each row:" << endl;
 cout << res << endl;
	Matrix3d m = Matrix3d::Random();
	cout << "Here is the matrix m:" << endl << m << endl;
	Matrix<ptrdiff_t, 3, 1> res = (m.array() >= 0.5).rowwise().count();
	cout << "Here is the count of elements larger or equal than 0.5 of each row:" << endl;
	cout << res << endl;