In certain least squares fit problems with a very large number of parameters the set of parameters can be divided into two classes, global and local parameters. Local parameters are those parameters which are present only in subsets of the data. Detector alignment and calibration is one of the problems, where the interest is only in optimal values of the global parameters. A method to solve the linear least square problem, irrespectively of the number of local parameters, is derived in the paper. A practical limit for the number of global parameters is between one thousand and ten thousand. The paper includes a description of a general program package Millepede for the efficient solution. A new faster version (2000/10/17) includes an option for online applications.
There is a source file (see below) containing the specific subprograms and a few general programs. The first file contains an example program, which may be called in a main program:
CALL TESTMP(0)
CALL TESTMP(1)
END