Polynomial Estimators

You can compute and display the least-squares polynomial curve of a specified degree using the Polynomial tab. There are two parameters and one button on the Polynomial tab:

• Degree: You can set the degree of the polynomial used to fit the data. Valid values for this field are in the range [0, M] where M=min(30, N−1) and where N is the number of non-missing observations in the scatter plot variables. The default value for this field is 1, which gives a line of least squares error.
• Bins: You can specify the number of locations at which the polynomial model is evaluated. Valid values are in the range [3, 500]. The default value for this field is 50, which means that the range of the horizontal data is subdivided into 50 evenly spaced points, and the polynomial is evaluated at each point. The curve displayed in the scatter plot is interpolated from those evaluation points.
• Add/Modify Curve: You can use this button either to create a new curve with the specified properties or to modify an existing curve.