To change from least squares to a robust fitting method, use the Method menu. In the below example, the exponential curve is shown. Polyval Matlab in build function is used. To change the type of confidence intervals, use the Bounds menu. example of the polynomial curve, in which the polyfit syntax is used. To change the degree of the polynomial, choose from the pop-up menu at the top of the figure. randtool - GUI tool for generating random numbers. polytool - Interactive graph for prediction of fitted polynomials. lsline - Add least-square fit line to scatter plot. The argument n controls the degree of the polynomial fit. hist3 - Three-dimensional histogram of bivariate data.
Matlab polytool update#
The predicted value of y will update as you drag the reference line. 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 can be dragged. First step: choose a model and determine its set of parameters. Polytool fits by least-squares using the regression modelĮvaluate the function by typing a value in the x-axis edit box or by dragging the vertical reference line on the plot. Matlab can tweak parameters to fit an arbitrary model to a data set. The polytool demo has the following features: A graph of. Plots 100(1-alpha) % confidence intervals on the predicted values. The polytool demo is an interactive graphic environment for polynomial curve fitting and prediction. Text with current predicted value of y and its uncertainty appears to the left of the y-axis. The plot shows the fitted curve and 95% global confidence intervals on a new predicted value for the curve. Note that predicted Y values are within DELTA of the integer X in every case. Then use polyfit to estimate the polynomial coefficients. Simulate the function y x, adding normal random errors with a standard deviation of 0.1. This plot is graphic user interface for exploring the effects of changing the polynomial degree of the fit. The polyval function is part of the standard MATLAB language. You can use the interface to explore the effects of changing the parameters of the fit and to export fit results to the workspace. Interactive plot for prediction of fitted polynomialsįits a line to the column vectors x and y and displays an interactive plot of the result. polytool(x,y) fits a line to the vectors x and y and displays an interactive plot of the result in a graphical interface. Polytool (Statistics Toolbox) Statistics Toolbox