X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Flinal%2Fsquarematrix.h;h=b8531aafcb8359bcda6ea35628a9f561f77b677b;hb=fb1e198;hp=ee86e13921219702fa58a682c4b5ab2bb5cfb290;hpb=e0d926c9c177ec28f1aaf326a6921438de9db9a3;p=libs%2Fmath.git

diff --git a/source/linal/squarematrix.h b/source/linal/squarematrix.h
index ee86e13..b8531aa 100644
--- a/source/linal/squarematrix.h
+++ b/source/linal/squarematrix.h
@@ -1,19 +1,17 @@
 #ifndef MSP_LINAL_SQUAREMATRIX_H_
 #define MSP_LINAL_SQUAREMATRIX_H_
 
-#include <stdexcept>
+#include <cmath>
 #include "matrix.h"
+#include "matrixops.h"
 
 namespace Msp {
 namespace LinAl {
 
-class not_invertible: public std::domain_error
-{
-public:
-	not_invertible(): domain_error(std::string()) { }
-	virtual ~not_invertible() throw() { }
-};
-
+/**
+A mathematical matrix with S rows and columns.  Some operations are provided
+here that are only possible for square matrices.
+*/
 template<typename T, unsigned S>
 class SquareMatrix: public Matrix<T, S, S>
 {
@@ -49,46 +47,16 @@ template<typename T, unsigned S>
 SquareMatrix<T, S> &SquareMatrix<T, S>::invert()
 {
 	SquareMatrix<T, S> r = identity();
-	for(unsigned i=0; i<S; ++i)
-	{
-		if(this->element(i, i)==T(0))
-		{
-			unsigned pivot = i;
-			for(unsigned j=i+1; j<S; ++j)
-				if(abs(this->element(j, i))>abs(this->element(pivot, i)))
-					pivot = j;
-
-			if(pivot==i)
-				throw not_invertible();
-
-			this->exchange_rows(i, pivot);
-			r.exchange_rows(i, pivot);
-		}
-
-		for(unsigned j=i+1; j<S; ++j)
-		{
-			T a = -this->element(j, i)/this->element(i, i);
-			this->add_row(i, j, a);
-			r.add_row(i, j, a);
-		}
-
-		T a = T(1)/this->element(i, i);
-		this->multiply_row(i, a);
-		r.multiply_row(i, a);
-	}
-
-	for(unsigned i=S; i-->0; )
-		for(unsigned j=i; j-->0; )
-			r.add_row(i, j, -this->element(j, i));
-
+	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