BIB-VERSION:: CS-TR-v2.0 ID:: STAN//CS-TR-78-697 ENTRY:: June 22, 1995 ORGANIZATION:: Stanford University, Department of Computer Science TITLE:: On the linear least squares problem with a quadratic constraint TYPE:: Technical Report AUTHOR:: Gander, Walter DATE:: November 1978 PAGES:: 62 ABSTRACT:: In this paper we present the theory and practical computational aspects of the linear least squares problem with a quadratic constraint. New theorems characterizing properties of the solutions are given and extended for the problem of minimizing a general quadratic function subject to a quadratic constraint. For two important regularization methods we formulate dual equations which proved to be very useful for the applications of smoothing of datas. The resulting algorithm is a numerically stable version of an algorithm proposed by Rutishauser. We show also how to choose a third order iteration method to solve the secular equations. However we are still far away from a foolproof machine independent algorithm. NOTES:: [Adminitrivia V1/Prg/19950622] END:: STAN//CS-TR-78-697