Hi Rooters,
I am using TFumili class (not Fumili2 from the minuit2 package) to do some detector calibration recently. I made use of the methods SetData() and SetUserFunc() to set data point and model function respectively. The code was compiled successfully but crashed during execution. I then carefully checked the source code of relevant methods of TFumili class and found the following which I think might be some bug:
- In the SGZ() method there is a block of code like this:
for (l=0;l<fNED1;l++) { // cycle on all exp. points
/* Some code in this loop*/
l = 0;
for (i=0;i<n;i++)
for (j=0;j<=i;j++)
fZ[l++] += df[i]*df[j];
k2 += fNED2;
} /* loop ends */l is a loop variable. However, l is set to 0 and represents the indices of elemets of array fZ towards the end of the loop, which causes l to end up with always the same value after one execution of the code in the loop. In that way, the loop might never end. I think it makes more sense if a new variable is defined to serve the purpose of looping over the array elements.
- In the ExecuteCommand() method there is such a code block:
Int_t TFumili::ExecuteCommand(const char *command, Double_t *args, Int_t nargs){
/* Some code */
if (nargs<=0) fCmPar[0] = 0;
Int_t i;
for(i=0;i<fMaxParam;i++) {
if(i<=nargs) fCmPar[i] = args[i];
}nargs is the number of elements in the array args from my understanding, so I did the following in my code:
But this turns out to crash the program since it tries to access the array element args[0], but args is NULL pointer. I believe it makes more sense if we change
to
We want to access the array args only when nargs>0.
I modified the code accordingly and the program works fine after that. Thus I believe they might be some bug and it is better to fix them.
BTW, I am using root 5.34 now. But I checked the code in root 6.02 and they are the same as that in 5.34.
Thanks.