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Title: LCLSQ: an implementation of an algorithm for linearly constrained linear least-squares problems. [For IBM 370 and 3033, in FORTRAN]

Technical Report ·
DOI:https://doi.org/10.2172/6778440· OSTI ID:6778440

This report describes the implementation of an algorithm of Stoer and Schittkowski for solving linearly constrained linear least-squares problems. These problems arise in many areas, particularly in data fitting where a model is provided and parameters in the model are selected to be a best least-squares fit to known experimental observations. By adding constraints to the least-squares fit, one can force user-specified properties on the parameters selected. The algorithm used applies a numerically stable implementation of the Gram-Schmidt orthogonalization procedure to deal with a factorization approach for solving the constrained least-squares problem. The software developed allows for either a user-supplied feasible starting point or the automatic generation of a feasible starting point, redecomposition after solving the problem to improve numerical accuracy, and diagnostic printout to follow the computations in the algorithm. In addition to a description of the actual method used to solve the problem, a description of the software structure and the user interfaces is provided, along with a numerical example. 3 figures, 1 table.

Research Organization:
Argonne National Lab. (ANL), Argonne, IL (United States)
DOE Contract Number:
W-31-109-ENG-38
OSTI ID:
6778440
Report Number(s):
ANL-80-116
Country of Publication:
United States
Language:
English