R. J. Renka
Abstract
The primary purpose of TSPACK is to construct a smooth function which interpolates a discrete set of data points. The function may be required to have either one or two continuous derivatives. If the accuracy of the data does not warrant interpolation, a smoothing function (which does not pass through the data points) may be constructed instead. The fitting method is designed to avoid extraneous inflection points (associated with rapidly varying data values) and preserve local shape properties of the data (monotonicity and convexity), or to satisfy the more general constraints of bounds on function values or first derivatives. The package also provides a parametric representation for construction general planar curves and space curves.
Supplemental Material
Available for Download
tension spline curve-fitting package Gams: e1a, e1c, k1a1a1, k1a1a3
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Index Terms
- Algorithm 716: TSPACK: tension spline curve-fitting package
Recommendations
Scalar- and planar-valued curve fitting using splines under tension
The spline under tension was introduced by Schweikert in an attempt to imitate cubic splines but avoid the spurious critical points they induce. The defining equations are presented here, together with an efficient method for determining the necessary ...
Algorithm 893: TSPACK: tension spline package for curve design and data fitting
TSPACK is a curve-fitting package based on exponential tension splines with automatic selection of tension factors. It serves both as a method for data fitting with preservation of shape properties or more general constraints, and as a means of computer ...
Remark on Algorithm 716
The curve-fitting package TSPACK has been converted to double precision. Also, portability has been improved by eliminating some potential errors.
Comments