Spline Toolbox Release Notes    

Chapter 2
Spline Toolbox 3.0 Release Notes

New Features

This section introduces the new features and enhancements added in the Spline Toolbox 3.0 since the Spline Toolbox 2.0.1 (Release 11.0).

Spline Tool Provides a Visual Interface to the Spline Toolbox

The splinetool function invokes a new visual interface that allows you to:

Automatic Knot Choice Simplifies Use of spapi and spap2

Until this release, if you wanted to construct a spline interpolant to given data, you had to specify the spline space from which this spline was to be chosen, by providing an appropriate knot sequence. Starting with this release, if you are not so certain about how to choose knots, you can simply specify the order of the spline to be used instead, and spapi will provide a suitable knot sequence.

The same difficulty of having to choose a knot sequence occurred in the construction of a least-squares spline approximation to given data, and here, too, you can instead merely specify the number of polynomial pieces of the given order to be used in the approximating spline in spap2.

Automatic Smoothing Parameter Choice Simplifies Use of csaps

You can now use csaps without specifying the smoothing parameter to be used. If none is specified, csaps will optionally return the one it chose for the given data, for further experimentation.

Use of Rational Splines

The relevant function functions (e.g., fnval, fnplt, fntlr, fnbrk, fnrfn, fn2fm, etc.) can now operate on rational splines (NURBS). Specific examples of a rational spline are provided by rsmak. Both rsmak and rpmak are available to generate arbitrary rational splines in B-form and ppform, respectively.

B-Spline Visual Interface

Splines in the Spline Toolbox are constructed as a linear combination of B-splines. Run bspligui to show how such a B-spline varies as you vary its knots. You can:

Other New Functions

The following functions have been added in the Spline Toolbox 3.0:

Other Enhancements

  Upgrading from an Earlier Release Major Bug Fix