Obtaining the equation type of an interpolated function

Asked Jun 18 '19 at 15:00

Active Jun 18 '19 at 15:43

Viewed 52 times

I used InterpolatingFunction on a set of points.

How can I know the type of that equation ? (polynomial, sinusoidal, logarithmic,etc...). I am looking for a general case answer.

Here is an example of dataset (among others, not necessarely of the same shape):

{-0.21970434400207, -0.22136596455224, -0.22074715867415, -0.21931620134959, -0.21774957192979, -0.21641976791018,-0.21554440918856, -0.21524028316217}

edited Jun 18 '19 at 15:43

asked Jun 18 '19 at 15:00

Alex

1

Could you use FindFormula on the discrete data? – Chris K Jun 18 '19 at 15:06
While FindFormula is indeed working for the simplest cases, it often breaks down for complicated functions. – Alex Jun 18 '19 at 15:28
I imagine it's a tricky problem in general. Could you post some data sets that cause problems? – Chris K Jun 18 '19 at 15:32
I just edited my question by giving an exemple. Hopefully this is a good one. For me the formula breaks down at the minima. – Alex Jun 18 '19 at 15:43
Unfortunately, PiecewiseExpand does not work on InterpolatingFunction objects, even though that should be a straightforward case. Has anyone found a workaround for this lack of functionality? – Roman Jun 18 '19 at 20:28
2

If by "that equation" you mean the InterpolatingFunction, then the InterpolatingFunction does piecewise polynomial interpolation, cubic by default. See this Q&A, for instance. – Michael E2 Jun 18 '19 at 21:32

Obtaining the equation type of an interpolated function

0 Answers0