From dfa93697792c10785505eb74099ccfb415096f7e Mon Sep 17 00:00:00 2001
From: Jiri Pittner <jiri@pittnerovi.com>
Date: Tue, 3 Mar 2026 15:26:14 +0100
Subject: [PATCH] some tests of matrix log

---
 t.cc | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/t.cc b/t.cc
index 9c319a2..066dd75 100644
--- a/t.cc
+++ b/t.cc
@@ -4707,7 +4707,7 @@ cout <<x;
 cout <<"Error = "<< (a*x-b).norm()<<endl;
 }
 
-if(1)
+if(0)
 {
 NRMat<double> a;
 NRMat<double> b;
@@ -4718,5 +4718,33 @@ cout <<x;
 cout <<"Error = "<< (a*x-b).norm()<<endl;
 }
 
+if(0)
+{
+int n;
+cin>>n;
+NRMat<double> a(n,n);
+a.randomize(.5);
+NRMat<double>  ae = exp(a);
+NRMat<double> aa = log(ae);
+cout <<a;
+cout <<aa;
+cout <<"Error = "<<(a-aa).norm()<<endl;
+}
+
+
+if(1)
+{
+int n;
+cin>>n;
+NRMat<double> a(n,n);
+a.randomize(.5);
+NRMat<double>  ax = a.transpose()*a;
+NRMat<double> al = log(ax);
+NRMat<double> aa = exp(al);
+cout <<ax;
+cout <<aa;
+cout <<"Error = "<<(ax-aa).norm()<<endl;
+}
+
 
 }//main