The Exact Condition of the B-Spline Basis May be Hard to Determine

Abstract

The author's conjecture concerning the knot sequence whose associate B-spline sequence has maximum max-norm condition number is disproved. Related condition numbers are explored and the corresponding conjecture concerning the 'worst' knot sequence for them is further supported by numerical results. There is numerical evidence that, in calculations devoted to bounding the p-norm condition number of the (appropriately scaled) B-spline basis, the extreme case occurs for a knot sequence without interior knots, while simple numerical examples show this not to be the case for the max-norm condition number itself. This is disappointing since it is only in the latter case that there seems to be a formula available for the condition number when there are no interior knots. Hence, even if the worst-case conjecture for the bound calculations for the p- norm condition number were proved, it would, offhand, not help in settling the problem of interest.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1988
Accession Number
ADA204080

Entities

People

  • Carl R. de Boor

Organizations

  • University of Wisconsin–Madison

Tags

DTIC Thesaurus Topics

  • Boundaries
  • Chebyshev Polynomials
  • Coefficients
  • Computations
  • Contrast
  • Convergence
  • Interlacing
  • Intervals
  • Military Research
  • North Carolina
  • Polynomials
  • Sequences
  • Step Functions
  • Symmetry
  • Test And Evaluation
  • Wisconsin

Fields of Study

  • Mathematics

Readers

  • Calculus or Mathematical Analysis
  • Oceanography.
  • Operations Research