sfit

Constructor for sfit object

Syntax

surfacefit = sfit(fittype,coeff1,coeff2,...)


Description

An sfit object encapsulates the result of fitting a surface to data. They are normally constructed by calling the fit function, or interactively by exporting a fit from the Curve Fitting app to the workspace. You can get and set coefficient properties of the sfit object.

You can treat an sfit object as a function to make predictions or evaluate the surface at values of X and Y.

Like the cfit class, sfit inherits all fittype methods.

surfacefit = sfit(fittype,coeff1,coeff2,...) constructs the sfit object surfacefit using the model type specified by the fittype object and the coefficient values coeff1, coeff2, etc.

Note

sfit is called by the fit function when fitting fittype objects to data. To create a sfit object that is the result of a regression, use fit.

You should only call sfit directly if you want to assign values to coefficients and problem parameters of a fittype object without performing a fit.

Methods of sfit objects:

argnames	Input argument names of cfit, sfit, or fittype object
category	Category of fit of cfit, sfit, or fittype object
coeffnames	Coefficient names of cfit, sfit, or fittype object
coeffvalues	Coefficient values of cfit or sfit object
confint	Confidence intervals for fit coefficients of cfit or sfit object
dependnames	Dependent variable of cfit, sfit, or fittype object
differentiate	Differentiate cfit or sfit object
feval	Evaluate cfit, sfit, or fittype object
formula	Formula of cfit, sfit, or fittype object
indepnames	Independent variable of cfit, sfit, or fittype object
islinear	Determine if cfit, sfit, or fittype object is linear
numargs	Number of input arguments of cfit, sfit, or fittype object
numcoeffs	Number of coefficients of cfit, sfit, or fittype object
plot	Plot cfit or sfit object
predint	Prediction intervals for cfit or sfit object
probnames	Problem-dependent parameter names of cfit, sfit, or fittype object
probvalues	Problem-dependent parameter values of cfit or sfit object
quad2d	Numerically integrate sfit object
setoptions	Set model fit options
sfit	Constructor for sfit object
type	Name of cfit, sfit, or fittype object

Examples

You can treat an sfit object as a function to make predictions or evaluate the surface at values of X and Y, e.g.,

        x = 3 - 6 * rand( 49, 1 );
        y = 3 - 6 * rand( 49, 1 );
        z = peaks( x, y );
        sf = fit( [x, y], z, 'poly32' );
        zhat = sf( mean( x ), mean( y ) )