The following example books and fills a histogram and Ntuple. See Chapters 7 and 8 for explanations of the ALPHA variables used.
SUBROUTINE QUINIT
CHARACTER*4 TAGS(2)
DATA TAGS/'ECHG','NTRK'/
C--- Book histogram to store momentum distribution for all charged
C--- tracks.
CALL QBOOK1(1,'Momentum',100,0.,50.,0.)
C--- Book Ntuple to store charged energy and number of charged tracks
C--- per event.
CALL QBOOKN(1000,'Event parameters',2,TAGS)
END
SUBROUTINE QUEVNT (QT,KT,QV,KV)
C-----------------------------------------------------------------------
INCLUDE 'PHYINC:QCDE.INC' !VAX
DIMENSION QT(KCQVEC,1), KT(KCQVEC,1), QV(KCQVRT,1), KV(KCQVRT,1)
INCLUDE 'PHYINC:QMACRO.INC' !VAX
C-----------------------------------------------------------------------
IF(KNCHT.EQ.0)RETURN
ECHRG=0.
C
C--- sum energy; histogram track momentum
C
DO 20 IT=KFCHT,KLCHT
ECHRG=ECHRG+QE(IT)
CALL HF1(1,QP(IT),1.)
20 CONTINUE
CALL QHFN(1000,ECHRG,FLOAT(KNCHT))
END