Hi Rene, I think Ursula Berthon already talked to you about this at the Root-Meeting: Within H1 we would like to be able to put bit-arrays into our HAT tree which should be accessible using only a browser and which is used for event selection. Currently TBits allows to use the member function TestBitNumber() which is quite inconvenient if it comes to a selection of a large number of status bits e.g. to check if the quality of an event is good. This could easily go over the maximum selection length of a tree. Therefore it would be nice if one could simply use bits[i] to check the ith bit in TBits bits. In addition it would be nice if one could view a bit-array in a TBrowser. It should show a histogram over the bits and the number of entries per bit. Currently fAllBits shows the entries (in 2^i form) for the lowest byte. I think this is not really useful. In the moment we are using byte-arrays which at least allow to use the [] operator and allow us to inspect one bit with the TBrowser. H1 would be very intersted to move to TBits because currently the bit-arrays make up most of our HAT ntuple, we would be even willing to move to a newer root-version ;-) Cheers, Birger ------------------------------------------------------------ Birger Koblitz koblitz@mail.desy.de MPI für Physik c/o DESY-FH1 Tel: +49 40 8998-2431 Notkestr. 85 Fax: +49 40 8998-3094 D-22603 HAMBURG
This archive was generated by hypermail 2b29 : Sat Jan 04 2003 - 23:51:16 MET