From 6e26844a6f1273b3d8dab1de869eeff3b93624ae Mon Sep 17 00:00:00 2001
From: Valentin Gehrke <madmaurice@zom.bi>
Date: Mon, 15 Feb 2016 13:01:02 +0100
Subject: [PATCH] Bug fix in gauss

---
 gauss.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/gauss.c b/gauss.c
index 178a108..c0a37ea 100644
--- a/gauss.c
+++ b/gauss.c
@@ -102,15 +102,16 @@ int solve_gauss_rec(GLS m, int rowCol) {
     if( ISZERO(glsGet(m,rowCol,rowCol)) ) return 0;
 
     for(size_t row = rowCol+1; row < m.size; row++) {
-        if(ISZERO(glsGet(m,row, rowCol))) continue;
-        glsTransform(m, row, glsGet(m,rowCol,rowCol), rowCol, - glsGet(m,row,rowCol) );
+        if(!ISZERO(glsGet(m,row, rowCol)))
+            glsTransform(m, row, glsGet(m,rowCol,rowCol), rowCol, - glsGet(m,row,rowCol) );
         glsSet(m,row,rowCol, 0.0f);
     }
 
     if(!solve_gauss_rec(m, rowCol+1)) return 0;
 
-    for(size_t row = 0; row < rowCol; row--) {
-        glsTransform(m, row, glsGet(m,rowCol,rowCol), rowCol, - glsGet(m,row,rowCol) );
+    for(size_t row = 0; row < rowCol; row++) {
+        if(!ISZERO(glsGet(m,row,rowCol)))
+            glsTransform(m, row, glsGet(m,rowCol,rowCol), rowCol, - glsGet(m,row,rowCol) );
         glsSet(m,row,rowCol, 0.0f);
     }
 
@@ -129,9 +130,10 @@ int solve(GLS m) {
 
 int main( int argc, char *argv[] ) {
 
-    GLS m = glsCreate(2);
-    glsSet(m,0,0,2); glsSet(m,0,1,3); glsSetRS(m,0, 13);
-    glsSet(m,1,0,1); glsSet(m,1,1,2); glsSetRS(m,1, 8);
+    GLS m = glsCreate(3);
+    glsSet(m,0,0,3); glsSet(m,0,1,-1); glsSet(m,0,2,-1); glsSetRS(m,0, 0);
+    glsSet(m,1,0,1); glsSet(m,1,1,4);  glsSet(m,1,2,2);  glsSetRS(m,1, 4);
+    glsSet(m,2,0,0); glsSet(m,2,1,2);  glsSet(m,2,2,1);  glsSetRS(m,2, 1);
 
     printf("Input: \n");
     glsPrint(m);