Access by Fortran DO loops

In ALPHA, fortran DO loops can be used to loop over most types of objects. For each type of object, three variables are defined: KFxxx, KLxxx, KNxxx. xxx represents the type of object. The last letter of the variables is either T (tracklike) or V (vertex). DO loops must be made from KFxxx to KLxxx; KNxxx is the number of objects of type xxx.

For example, the following three lines will make a histogram of the momentum spectrum of charged particles.

              DO 10 ITK = KFCHT, KLCHT
                CALL HF1 (47,QP(ITK),1.)
         10   CONTINUE

KFCHT,KLCHT

number of first (last) charged track.

ITK

loop index = ALPHA track number

QP(ITK)

momentum of track ITK (see 8.1.1)

The number of charged tracks is given by the variable KNCHT. KNCHT stands for KLCHT - KFCHT + 1. Therefore, if KNCHT = 0, KLCHT = KFCHT - 1.

The objects which can be accessed with these DO loops are listed in the following two sections.