Fitgrid Introduction

Fitgrid functionality

Fitgrid is a package in the ngmath library for interpolating one-dimensional and two-dimensional data. The package has the following functionality: See the comparative analysis of the ngmath packages for details on which ngmath package is most appropriate for your problem.

Fitgrid algorithm

The functions in Fitgrid utilize splines under tension for the interpolations. Splines under tension are controlled by a scalar tension factor that can be adjusted to provide a smooth transition from cubic spline interpolation to linear interpolation. To do its interpolations, Fitgrid fits a tension spline to the input data and then picks its interpolated values from the fitted spline function.

The documentation for Natgrid contains a general discussion of interpolation algorithms.

Fitgrid history

Fitgrid is based on Alan Cline's package Fitpack, an early version of which is available from netlib. Fitpack uses splines under tension to interpolate in one and two dimensions. An expanded version of Fitpack, as well as complete hardcopy documentation, can be obtained from: Pleasant Valley Software, 8603 Altus Cove, Austin TX 78759. Dr. Cline has our great gratitude for allowing us to incorporate his early version of Fitpack into the ngmath library.

Learning how to use Fitgrid

You should now proceed to the module on learning how to use Fitgrid.
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