\sum E over 3x3

Simple implementation :

1. find the element (eta,phi) with maximum energy
2. sum the 3x3 elements aroud this one and consider this as the total energy

The number of events with negative total energy is reduced: now it's 605 over 45165 (it was 811 over 45165). Their values are now in the range [0.;-9.] and most of them are around -6 (it was aroud -50). Are these evts due to fake triggers? of yes, why? am I allowed to simply discard them?

The new energy distributionnow looks like this:
the mean value is different from previously (it was 243 -- nominal 300).