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polytool

Interactive plot for prediction of fitted polynomials.

Syntax

Description

polytool(x,y) fits a line to the column vectors, x and y, and displays an interactive plot of the result. This plot is graphic user interface for exploring the effects of changing the polynomial degree of the fit. The plot shows the fitted curve and 95% global confidence intervals on a new predicted value for the curve. Text with current predicted value of y and its uncertainty appears left of the y-axis.

polytool(x,y,n) initially fits a polynomial of order, n.

polytool(x,y,n,alpha) plots 100(1-alpha)% confidence intervals on the predicted values.

polytool fits by least-squares using the regression model,


Evaluate the function by typing a value in the x-axis edit box or dragging the vertical reference line on the plot. The shape of the pointer changes from an arrow to a cross hair when you are over the vertical line to indicate that the line is draggable. The predicted value of y will update as you drag the reference line.

The argument, n, controls the degree of the polynomial fit. To change the degree of the polynomial, choose from the pop-up menu at the top of the figure.

When you are done, press the Close button.


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