User`s guide

Preface
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What Is the Curve Fitting Toolbox?
The Curve Fitting Toolbox is a collection of graphical user interfaces (GUIs)
and M-file functions built on the MATLAB
®
technical computing environment.
The toolbox provides you with these main features:
• Data preprocessing such as sectioning and smoothing
• Parametric and nonparametric data fitting:
- You can perform a parametric fit using a toolbox library equation or using
a custom equation. Library equations include polynomials, exponentials,
rationals, sums of Gaussians, and so on. Custom equations are equations
that you define to suit your specific curve fitting needs.
- You can perform a nonparametric fit using a smoothing spline or various
interpolants.
• Standard linear least squares, nonlinear least squares, weighted least
squares, constrained least squares, and robust fitting procedures
• Fit statistics to assist you in determining the goodness of fit
• Analysis capabilities such as extrapolation, differentiation, and integration
• A graphical environment that allows you to:
- Explore and analyze data sets and fits visually and numerically
- Save your work in various formats including M-files, binary files, and
workspace variables
Exploring the Toolbox
The Curve Fitting Toolbox consists of two different environments: a graphical
user interface (GUI) environment and the usual MATLAB command line
environment.
Although the two environments are functionally equivalent, you generally
cannot mix the two when performing a given curve fitting task. For example,
you cannot generate a fit at the command line and then import that fit into the
graphical environment. However, you can create a fit in the graphical
environment and then generate an associated M-file. You can then recreate the
fit from the command line and modify the M-file according to your needs. For
this reason, as well as for the enhanced data analysis and exploration tools that
are available, we recommend you use the graphical environment for most
tasks.