How to calculate the deviation of points from a curve?

[MelanieBrett]

Hi,
I'm working on some coursework for which I have been modelling a curve to a set of points, and for the final section I am wanting to calculate how close each point is to the curve as a method of comparison between the curves I have calculated. Some of the curves are quadratic, and others are the Cartesian form of some Polar equations. If anyone could offer any help or advice, it would be much appreciated :)

 

[bhillyard]

You could try calculating the average distance of each set of points from the curve - perhaps better to look at the root mean square distance. Essentialy the standard deviation of the points from the curve.

 

[Svein]

You would usually do a chi-square test (https://en.wikipedia.org/wiki/Chi-squared_test).