Introduction
You can evaluate (interpolate or extrapolate), differentiate, or integrate a fit over a specified data range with the Analysis GUI. You open this GUI by pressing Analysis on the Curve Fitting Tool.
For this example, you will extrapolate the quadratic polynomial fit to predict the US population from the year 2000 to the year 2050 in 10 year increments. To do so, enter the appropriate data vector in the Analyze at Xi field, select the Evaluate fit at Xi check box, and then press the Apply button. The numerical extrapolation results are shown below.
By selecting the Plot results and Plot data set check boxes, and pressing Apply, you can plot the extrapolated values and the data in a new figure window.
Saving the analysis results
Press the Save to workspace button to save the extrapolated values as a structure to the workspace.
The resulting analysis structure is shown below.
analysisresults
analysisresults =
xi: [6x1 double]
yfit: [6x1 double]