Splines and the Logarithmic Function.

Abstract

Let q be fixed, q>1, and let f(x) = log x/log q in (0, pos infinity). The paper determines the unique spline function (S sub n)(x), of degree n, defined in (0, pos infinity) and having as knots the points of the sequence (q sup nu) (neg infinity < nu < infinity), such as to satisfy the conditions (S sub n)(qx) = (Sub n)(x) + 1 if x>0, and (S sub n)(1) = 0. It follows that (S sub n)(q nu) = f(q sup nu) for all integers nu. It is shown that (S sub n)(x) shares with f(x) its monotonicity properties of hither order. Nevertheless and against all expectations it is shown that (S sub n)(x) does not converge to f(x) as n nears infinity. Most of the paper is devoted to an analysis of the peculiar asymptotic behavior of (S sub n)(x).

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1974
Accession Number
ADA001664

Entities

People

  • D. J. Newman
  • Isaac Jacob Schoenberg

Organizations

  • University of Wisconsin–Madison

Tags

DTIC Thesaurus Topics

  • Sequences

Fields of Study

  • Mathematics

Readers

  • Analytical Mechanics
  • Approximation Theory.