fix bug #30166, thanks to Chul Su Park

git-svn-id: http://root.cern.ch/svn/root/trunk@20301 27541ba8-7e3a-0410-8455-c3a389f83636

hist/src/TF1Helper.cxx

@@ -17,6 +17,8 @@
 #include <cmath>
 #include <cassert>
 
+#include <iostream>
+
 namespace ROOT { 
 
 
@@ -83,8 +85,10 @@ double IntegralError(TF1 * func, double a, double b, double epsilon) {
    double err2 = 0; 
    for (int i = 0; i < nfreepar; ++i) { 
       double s = 0;
-      for (int j =0; j < nfreepar; ++j) 
-         s += ig[j] * covMatrix[i*nfreepar + j] ;
+      for (int j =0; j < nfreepar; ++j) {
+         std::cout << i << "  " << j << " ig " << ig[i] << "  " << ig[j] << "  " << covMatrix[i*npar + j] << "  " << s << std::endl;  
+         s += ig[j] * covMatrix[i*npar + j] ;
+      }
 
       err2 += ig[i] * s; 
    }