From fb1e19889b85112eca096d7ec55b318859cea333 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 9 Nov 2017 12:07:20 +0200
Subject: [PATCH] Rename the low-level matrix inversion function to
 gauss_jordan

Since that's the name of the algorithm being used.  Also remove an
unnecessary assignment from the non-mutating case.
---
 source/linal/matrixops.h    | 4 ++--
 source/linal/squarematrix.h | 8 +++++---
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/source/linal/matrixops.h b/source/linal/matrixops.h
index 5bf9f43..84c8012 100644
--- a/source/linal/matrixops.h
+++ b/source/linal/matrixops.h
@@ -17,7 +17,7 @@ public:
 
 
 template<typename T>
-inline T &invert_matrix(T &m, T &r)
+inline T &gauss_jordan(T &m, T &r)
 {
 	typedef typename T::ElementType V;
 	using std::abs;
@@ -54,7 +54,7 @@ inline T &invert_matrix(T &m, T &r)
 		for(unsigned j=i; j-->0; )
 			r.add_row(i, j, -m.element(j, i));
 
-	return m = r;
+	return r;
 }
 
 } // namespace LinAl
diff --git a/source/linal/squarematrix.h b/source/linal/squarematrix.h
index 0a97e61..b8531aa 100644
--- a/source/linal/squarematrix.h
+++ b/source/linal/squarematrix.h
@@ -47,14 +47,16 @@ template<typename T, unsigned S>
 SquareMatrix<T, S> &SquareMatrix<T, S>::invert()
 {
 	SquareMatrix<T, S> r = identity();
-	return invert_matrix(*this, r);
+	gauss_jordan(*this, r);
+	return *this = r;
 }
 
 template<typename T, unsigned S>
 inline SquareMatrix<T, S> invert(const SquareMatrix<T, S> &m)
 {
-	SquareMatrix<T, S> r = m;
-	return r.invert();
+	SquareMatrix<T, S> temp = m;
+	SquareMatrix<T, S> r = SquareMatrix<T, S>::identity();
+	return gauss_jordan(temp, r);
 }
 
 } // namespace LinAl
-- 
2.45.2