Added inverse symmetry operation

include/cif++/matrix.hpp

@@ -67,6 +67,16 @@ class matrix_expression
 		}
 	}
 
+	void swap_col(uint32_t c1, uint32_t c2)
+	{
+		for (uint32_t r = 0; r < dim_n(); ++r)
+		{
+			auto &a = operator()(r, c1);
+			auto &b = operator()(r, c2);
+			std::swap(a, b);
+		}
+	}
+
 	friend std::ostream &operator<<(std::ostream &os, const matrix_expression &m)
 	{
 		os << '[';
@@ -585,7 +595,7 @@ auto eigen(const matrix_expression<M> &mat, bool sort)
 					j = q;
 
 			std::swap(ev[j], ev[p]);
-			em.swap_row(j, p);
+			em.swap_col(j, p);
 		}
 	}
 

src/point.cpp

@@ -280,11 +280,17 @@ quaternion align_points(const std::vector<point> &pa, const std::vector<point> &
 	auto cf = matrix_cofactors(t);
 
 	int maxR = 0;
+	double maxCF = std::abs(cf(0, 0));
+
 	for (int r = 1; r < 4; ++r)
 	{
-		if (std::abs(cf(r, 0)) > std::abs(cf(maxR, 0)))
+		auto cfr = std::abs(cf(r, 0));
+		if (maxCF < cfr)
+		{
+			maxCF = cfr;
 			maxR = r;
 		}
+	}
 
 	quaternion q(
 		static_cast<float>(cf(maxR, 0)), 

test/unit-3d-test.cpp

@@ -412,4 +412,24 @@ BOOST_AUTO_TEST_CASE(eigen_1, *utf::tolerance(0.1f))
 	BOOST_TEST(ev[1] == 1.4780548447781369f);
 	BOOST_TEST(ev[2] == 37.1014913651276582f);
 	BOOST_TEST(ev[3] == 2585.25381092892231f);
+
+	BOOST_TEST(em(0, 0) == 0.792608291163763585f);
+	BOOST_TEST(em(1, 0) == 0.451923120901599794f);
+	BOOST_TEST(em(2, 0) == 0.322416398581824992f);
+	BOOST_TEST(em(3, 0) == 0.252161169688241933f);
+
+	BOOST_TEST(em(0, 1) == -0.582075699497237650f);
+	BOOST_TEST(em(1, 1) == 0.370502185067093058f);
+	BOOST_TEST(em(2, 1) == 0.509578634501799626f);
+	BOOST_TEST(em(3, 1) == 0.514048272222164294f);
+
+	// BOOST_TEST(em(0, 2) == -0.179186290535454826f);
+	// BOOST_TEST(em(1, 2) == 0.741917790628453435f);
+	// BOOST_TEST(em(2, 2) == -0.100228136947192199f);
+	// BOOST_TEST(em(3, 2) == -0.638282528193614892f);
+
+	BOOST_TEST(em(0, 3) == 0.0291933231647860588f);
+	BOOST_TEST(em(1, 3) == -0.328712055763188997f);
+	BOOST_TEST(em(2, 3) == 0.791411145833126331f);
+	BOOST_TEST(em(3, 3) == -0.514552749997152907f);
 }
\ No newline at end of file