From 25bcdd25e5f6806a847b957d016d421067cecfa5 Mon Sep 17 00:00:00 2001
From: Andreas Suter <andreas.suter@psi.ch>
Date: Thu, 3 Jul 2025 10:22:11 +0200
Subject: [PATCH] add err==0.0 handling for rounding.

---
 src/classes/PFitter.cpp | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/classes/PFitter.cpp b/src/classes/PFitter.cpp
index 923f39e6..20f92826 100644
--- a/src/classes/PFitter.cpp
+++ b/src/classes/PFitter.cpp
@@ -2943,9 +2943,13 @@ 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;