PolynomialRegression Package
![data = Table[{k, k^3 - k - 20 + Random[]}, {k, 10}]; CubicFit[data]](images/PolyRegressionPics_gr_1.gif)



Synopsis
This package provides commands to fit polynomials to bivariate data, and
display the resulting function superimposed on the data. A plot of the
residuals is also provided. It is intended as an instructional aid.
Commands
The following commands are provided in this package:
QuadraticFit[xdata, ydata]
gives the equation of the least-squares quadratic
function for the data, a scatterplot of the data with the quadratic
function superimposed, and a residual plot. It will take any options that
ListPlot takes. QuadraticFit[data], where data is a list of coordinate pairs
{{x1,y1},{x2,y2},...}, will give the same result.
CubicFit[xdata, ydata]
gives the equation of the least-squares cubic
function for the data, a scatterplot of the data with the cubic function
superimposed, and a residual plot. It will take any options that ListPlot
takes. CubticFit[data], where data is a list of coordinate pairs
{{x1,y1},{x2,y2},...}, will give the same result.
QuarticFit[xdata, ydata]
gives the equation of the least-squares quartic
function for the data, a scatterplot of the data with the quartic function
superimposed, and a residual plot. It will take any options that ListPlot
takes. QuarticFit[data], where data is a list of coordinate pairs
{{x1,y1},{x2,y2},...}, will give the same result.
PolynomialFit[xdata, ydata, n]
gives the equation of the least-squares
degree n polynomial for the data, a scatterplot of the data with the
polynomial superimposed, and a residual plot. It will take any options that
ListPlot takes. PolynomialFit[data,n], where data is a list of coordinate
pairs {{x1,y1},{x2,y2},...}, will give the same result.
Note that there is a LinearFit command in the
BasicRegression Package.
Last Updated: June 20, 2002