From 5c494684ab116abc5c9c9ca9bb7dcff11f305e46 Mon Sep 17 00:00:00 2001
From: Jiri Pittner <jiri@pittnerovi.com>
Date: Mon, 15 May 2023 15:47:33 +0200
Subject: [PATCH] added debug testing ipiv in linear_solve_do

---
 nonclass.cc | 11 ++++++++---
 t.cc        | 10 ++++++----
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/nonclass.cc b/nonclass.cc
index 14690ca..0a38db7 100644
--- a/nonclass.cc
+++ b/nonclass.cc
@@ -26,6 +26,8 @@
 #include "qsort.h"
 #include "fortran.h"
 
+#define IPIV_DEBUG
+
 
 namespace LA {
 
@@ -154,17 +156,20 @@ static void linear_solve_do(NRMat<double> &A, double *B, const int nrhs, const i
 		//find out whether ipiv are numbered from 0 or from 1
 		int shift=1;
 	        for (int i=0; i<n; ++i) if(ipiv[i]==0) shift=0;
+#ifdef IPIV_DEBUG
+       std::cout <<"shift = "<<shift<<std::endl;
+#endif
 		//change sign of det by parity of ipiv permutation
 		if(*det) for (int i=0; i<n; ++i) if(i+shift != ipiv[i]) {*det = -(*det); ++iswap;}
 	}
-/*
-       std::cout <<"iswap = "<<iswap<<std::endl;
 	if(det && r>0) *det = 0;
+#ifdef IPIV_DEBUG
+       std::cout <<"iswap = "<<iswap<<std::endl;
 
 	std::cout <<"ipiv = ";
 	for (int i=0; i<n; ++i) std::cout <<ipiv[i]<<" ";
 	std::cout <<std::endl;
-*/
+#endif
 
 	delete [] ipiv;
 	if (r>0 && B) laerror("singular matrix in lapack_gesv");
diff --git a/t.cc b/t.cc
index 525164d..b6214bf 100644
--- a/t.cc
+++ b/t.cc
@@ -1237,7 +1237,7 @@ cout <<r;
 }
 
 
-if(0)
+if(1)
 {
 int n,m;
 cin>>n >>m;
@@ -1254,10 +1254,12 @@ for(int i=0;i<n;++i) for(int j=0;j<m;++j)
 for(int i=0;i<n;++i) b[i] = i;
 
 NRVec<double> bb=b;
-//cout <<a;
+cout <<a;
 //cout <<b;
 NRMat<double>aa=a;
-linear_solve(aa,bb);
+double d;
+linear_solve(aa,bb,&d);
+cout <<"det = "<<d<<endl;
 //cout <<bb;
 gmres(a,b,x,1,1e-10,100,1,0,1,0);
 //conjgrad(a,b,x,1,1e-10,200,1,0,1);
@@ -2575,7 +2577,7 @@ cout <<test;
 cout <<"Error = "<<(expitszsz-test).norm()<<endl;
 }
 
-if(1)
+if(0)
 {
 NRVec<double> x({1,2,3});
 NRVec<double> y({4,5,6});