1. NAME AND TITLE

REGN: Code System for Solving Nonlinear Systems of Equations via the Gauss-Newton Method.

AUXILIARY ROUTINE

EXAMP: Test Program.

2. CONTRIBUTOR

Institute of Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia, Bulgaria.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

REGN solves nonlinear systems of numerical equations in difficult cases: high nonlinearity, poor initial approximations, a large number of unknowns, ill condition or degeneracy of a problem.

5. METHOD SOLUTION

REGN uses different variants of regularized iteration methods of the Gauss-Newton type.

6. RESTRICTIONS OR LIMITATIONS

The basic restriction is n < 200.

7. TYPICAL RUNNING TIME

The running time of the main algorithm depends upon the magnitude of the control E₀. The numeric differentiation being used slows down the iteration procedure.

8. COMPUTER HARDWARE REQUIREMENTS

REGN is operable on the IBM 360/370 computers

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran IV compiler is required.

10. REFERENCE

L. Alexsandrov, M. Drenska, and D. Karadjov, "The Programme Package REGN for Solving Nonlinear Systems of Equations by Means of Regularized Methods of the Gauss-Newton Type," Informal report.

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code and test program.

12. DATE OF ABSTRACT

April 1984.