CINT problem with TMath::Sort()

ROOT
1

Dear ROOTers

The following function did work in root_v5.18/00 w/o the need to compile it:

Double_t Median(Int_t n, const Double_t *arr)
{
   if (n == 1) return arr[0];

// Create index and sort array
   Int_t *index = 0;
   if (!(index = new Int_t[n])) {return 1;}
   TMath::Sort(n, arr, index);

// Find median
   Int_t k;
   Double_t median = 0;
   if ((n % 2) == 0){
      k = (Int_t)TMath::Floor(n / 2.0) - 1;
      median = (arr[index[k]] + arr[index[k+1]])/2;
   } else {
      k = (Int_t)TMath::Floor(n / 2.0);
      median = arr[index[k]];
   }//if

   delete [] index;

   return median;
}//Median

However, in root_v15.20/00 I get the following error:

Error: Function Sort(n,arr,index) is not defined in current scope

Replacing index with:

   Long64_t *index = 0;
//or:
//   long long *index = 0;
   if (!(index = new Long64_t[n])) {return 1;}

results in the following error:

Error: Symbol TMath is not defined in current scope

The problem is clearly the change in the definition of TMath::Sort() between root_v5.18/00 and root_v15.20/00.

It would be great if CINT could handle the new definitions w/o the need to compile, or alternatively the
old definition of TMath::Sort() could be added to TMath.

Best regards
Christian

2

It should be sufficient to do:

since in the dictionary only the instantiation of TMath::Sort with Long64_t is present. With this change it works for me.

Best Regards
Lorenzo

3

Dear Lorenzo

You are right, when simply testing function Median() everything seems to be fine, however it seems that my example was too simple.

For this reason I am attaching macro “macroTestMedian.C”. Now I get the following output on MacOS X 10.4.11:

root [0] .L macroTestMedian.C
root [1] TestWeights()       
Error: Symbol TMath is not defined in current scope  macroTestMedian.C:46:
*** Interpreter error recovered ***
root [2] .L macroTestMedian.C+
Info in <ACLiC>: script has already been loaded in interpreted mode
Info in <ACLiC>: unloading /Volumes/CoreData/ROOT/rootcode/xps-x.x.x/./macroTestMedian.C and compiling it
Info in <TUnixSystem::ACLiC>: creating shared library /Volumes/CoreData/ROOT/rootcode/xps-x.x.x/./macroTestMedian_C.so
root [3] TestWeights()        
w: - 0.0421298 - 0.0433799 - 0.0479173 - 0.0436661 - 0.043845 - 0.037824 - 0 - 0.0438016 - 0.0451288 - 0.0411797 - 0.049073 - 0.00238643 - 0.0370189 - 0.0496886 - 0.0496012 - 0.0497087 - 0.0432122 - 0.0438448 - 0.0424522 - 0.0497087 - 0.0496401 - 0.0485132 - 0.046909 - 0.0493705
root [4] .q

As you see, running the macro with CINT results in an error, while compiling it with ACLiC everything is ok!

As a second point I have a severe problem with the inconsistencies in TMath, see my new thread in “ROOT Discussion”.

Best regards
Christian
macroTestMedian.C (2.39 KB)

4

The problem is with this valid C++ code probably mis-interpreted by CINT
(nothing to do with TMath)

 max  = (TMath::Abs(x[i]) > max) ? TMath::Abs(x[i]) : max;

Anyway in this case, I think it is peferable to write the code as

 if  (TMath::Abs(x[i]) > max) max =  TMath::Abs(x[i]);

The other problem is in the doc (THTML) not TMath.

Regards

Lorenzo

5

Dear Lorenzo

Thank you for your suggestion.

Testing the code I realized that simply replacing

max  = (TMath::Abs(x[i]) > max) ? TMath::Abs(x[i]) : max;

with

max  = (TMath::Abs(x[i]) > max) ? (TMath::Abs(x[i])) : max;

did also solve the problem.

Nevertheless I hope that this CINT problem will be solved.

Best regards
Christian