Find Maximum of THn?

Newbie
1

I am creating a four dimensional histogram, using THn. Now I want to normalize it. Previously, for lower dimensions, I used

hist -> Scale(1./hist -> GetMaximum());

but this does not work for THn. I get the error

error: no member named 'GetMaximum' in 'THn'

Any help would be appreciated!

2

Maybe @moneta or @Axel can help

3

Hi,

There is no such function in THn, but you can easily compute it, looping at the bins. Here is an example code, assuming the histogram is of double content type:

int n = hist->GetNbins();
auto & array = static_cast<TNDArrayT<double>&>(hist->GetArray())
std::vector<double> x(n);
std::generate(x.begin(), x.end(), [ibin=0]() mutable{ ibin++; return array.At(ibin);});
double maxValue = *(std::max_element(x.begin(),x.end());

Cheers

Lorenzo