Geography and the Properties of Surfaces. A Two-Dimensional Interpolation Function for Computer Mapping of Irregularly Spaced data,

Abstract

Techniques of interpolating from irregularly spaced known function values in two dimensions are discussed. First, a function defined as a weighted average of the given function values, with the weighting based on the inverse distance from the corresponding points, is explored. To shorten computation and improve the quality of interpolation, additional terms based on distances, directions and slopes are added. An interpolation function everywhere continuously differentiable and fitting the data exactly is finally presented. A provision for barriers to interpolation is described for applications in geographical analysis. The interpolation function has been incorporated into a computer mapping program in FORTRAN called SYMAP (Versions IV and V). (Author)

Document Details

Document Type
Technical Report
Publication Date
Mar 20, 1968
Accession Number
AD0668707

Entities

People

  • Donald Shepard

Organizations

  • Harvard University

Tags

DTIC Thesaurus Topics

  • Computations
  • Computers
  • Geography
  • Interpolation
  • Mathematical Analysis
  • Mathematics
  • Two Dimensional

Readers

  • Computer Science.
  • Computer Vision.
  • Statistical inference.

Technology Areas

  • Space
  • Space - Space Objects