From f9ddb4e6683831f5ddd5e07e7e2539a6a82b48c9 Mon Sep 17 00:00:00 2001
From: Andreas Suter <andreas.suter@psi.ch>
Date: Thu, 3 Jul 2025 10:19:09 +0200
Subject: [PATCH] handle err==0 for rounding.

---
 src/classes/PFitter.cpp | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/classes/PFitter.cpp b/src/classes/PFitter.cpp
index 113104fce..9b1466849 100644
--- a/src/classes/PFitter.cpp
+++ b/src/classes/PFitter.cpp
@@ -2311,6 +2311,17 @@ Bool_t PFitter::ExecuteSave(Bool_t firstSave)
   // CalcExpectedChiSquare handles both, chisq and mlh
   Bool_t ok;
   PDoubleVector par_r = ParamRound(param, err, ok);
+std::cout << "debug> ok=" << ok << std::endl;
+std::cout << "debug> param=";
+for (auto p : param) std::cout << p << ", ";
+std::cout << std::endl;
+std::cout << "debug> err=";
+for (auto e : param) std::cout << e << ", ";
+std::cout << std::endl;
+std::cout << "debug> par_r=";
+for (auto p : par_r) std::cout << p << ", ";
+std::cout << std::endl;
+  
   if (!ok)
     par_r = param;
   if (fDKSReady)
@@ -3198,9 +3209,13 @@ PDoubleVector PFitter::ParamRound(const PDoubleVector &par, const PDoubleVector
   int exp;
   double dval;
   for (unsigned int i=0; i<par.size(); i++) {
-    exp = round(log10(fabs(err[i])))-2;
-    dval = round(par[i]*pow(10.0, -exp))/pow(10.0, -exp);
-    par_r[i] = dval;
+	if (err[i] != 0.0) {	    
+      exp = round(log10(fabs(err[i])))-2;
+      dval = round(par[i]*pow(10.0, -exp))/pow(10.0, -exp);
+      par_r[i] = dval;
+    } else {
+      par_r[i] = par[i];
+    }
   }
   
   return par_r;