Spline Toolbox Release Notes    

Chapter 1
Spline Toolbox 3.1.1 Release Notes

New Features

This section summarizes the new features and enhancements introduced in the Spline Toolbox 3.1 since Version 3.0 (Release 12.1), and included in Version 3.1.1.

If you are upgrading from the Spline Toolbox 2.0, then you should also see New Features in the Spline Toolbox 3.0 Release Notes.

Smoothing Splines for Scattered Bivariate Data

The new command tpaps enables you to create thin-plate spline approximations f that satisfy, approximately or exactly, the equation for given data values z at given scattered data sites (x,y) in the plane. The associated collocation matrix is provided by stcol. You can also create the first-order derivatives of a thin-plate spline.

The spline created by tpaps is in stform, as are its first-order derivatives. You can create an stform directly from its centers and coefficients using stmak. As with all forms, you can evaluate the splines in stform with fnval, plot them with fnplt, etc.

See Fitting Values at Scattered 2-D Sites and The stform in the Spline Toolbox documentation for more information.

splinetool Command History M-File

In the Spline Tool GUI (splinetool), you can now generate a function M-file that you can use to generate, from the original data, any or all graphs currently in the GUI. Select File -> Save M-File to save the M-file.

This M-file also provides you with a written record of the Spline Toolbox commands used to generate the current graph(s), and can be edited, or executed in a loop over different data sets.

Spline-Specific Zero Finder

A new command fnzeros enables you to find an ordered list of the zeros of a univariate, scalar-valued spline, in its basic interval or in a specified interval.

Spline-Specific Minimum Finder

A new command fnmin enables you to obtain the minimum or maximum value of a univariate, scalar-valued spline as well as its location, in its basic interval or in a specified interval.

Function Summary

Version 3.1 of the Spline Toolbox provides the following:

New Functions

Minimum of a function in a given interval
Find zeros of a function in a given interval
Scattered translates collocation matrix
Put together a function in stform
Thin-plate smoothing spline

Spline Functions with New or Changed Capabilities

A new value of the part argument, 'variables', causes fnbrk to return the number of variables of the specified function.
As a new default, fnrfn now refines the partition (breaks or knots) of the given form by adding to it every midpoint. fnrfn previously had no default.
splinetool now permits the entry of a vector whose elements replace that many entries in the weights display, starting with the marked entry.

These functions now treat an empty optional argument the same as not having that optional argument.

  Spline Toolbox Release Notes Major Bug Fixes