Hello,
I am trying to convert gaussian significances to probabilities repeatedly
and quickly within some looping code.
What is the best way to do this? .. i have tried defining the erf and
integrating it but i'm not convinced root is giving me the correct
answers.. my code:
{
form1 = new TFormula("form1","pow(2.718281828,-pow(x,2))");
TF1 f1("func1","form1",-10,10);
f1.Draw();
double prob=f1.Integral(-1,1);
cout<<"returned integral is "<<prob<<endl;
cout<<"prob is "<<prob*pow( 1.77245,-1)<<endl;
// integral of -100 to 100 is 1.77245
}
returned integral is 1.49365
prob is 0.842703
..but i think i should get an answer closer to 63% within 1 standard
deviation of a gaussian??
<< root vers: 3.05/07>>
..can you see what i am doing wrong or suggest anything? ..maybe there is
a tutorial on this but i couldn't find it.
cheers,
Dan.
--
CMS-Bristol
http://cern.ch/dan.holmes
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