Curve Fitting Canvas Application Example 

In this example the user is asked to click on a plot to add points.  When 2 or more points are set, the application will find a polynomial curve fit approximation and draw that on the plot too.

The complete application source code is available here for you to inspect and modify.  It uses the Canvas package to describe the interface, and a ScriptButton with a onclick action and a State element to store hidden values.  An important point in this example is the use of the 'include' option to make sure the 'myView' variable is included into the button action code. 

https://learn.maplesoft.com/#/?d=JOESANAGLRBIJUFMNQPRKGBMGKPIEODNBGGSCSEGOINMOIMFOOMODLILPIASNREKAKERCTHSEPIOIRGUAQCTIKLSCMCTOIAUFOJP 

Next Steps 

Return to DocumentTools[Canvas] Overview Page