Timeline for Avoid Extrapolation When Using NMaximize on Interpolating Functions
Current License: CC BY-SA 4.0
15 events
| when toggle format | what | by | license | comment | |
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| Dec 12, 2021 at 6:00 | history | tweeted | twitter.com/StackMma/status/1469909929997840387 | ||
| Dec 11, 2021 at 17:24 | vote | accept | mathemagician617 | ||
| Dec 11, 2021 at 17:09 | answer | added | Michael E2 | timeline score: 4 | |
| Dec 11, 2021 at 16:28 | comment | added | mathemagician617 | @MichaelE2 thank you very much for your input I appreciate it. Do you have any suggestions on how I might be able to best visualize the results of the optimization? I'm struggling to find a good graphing method that will include all data (ie both logdata1 values and data2 values) because I have 3D inputs (the same for both functions) with two outputs (one from each function). | |
| Dec 11, 2021 at 16:25 | comment | added | Michael E2 |
I meant that numerical optimization is accompanied by some uncertainty unless the function is convex. For instance, an optimizer might reliably return a local minimum, but if there are many local minima, it might not return the global minimum. A reason to doubt the result is that it is greater than one of the data points (I didn't check). Or in the case of experimental data, if the minimum value or its location seems inconsistent with the physical setup. I see no reason to think that the extrapolation caused NMinimize to fail to work properly.
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| Dec 11, 2021 at 16:03 | comment | added | mathemagician617 | @MichaelE2 My apologies for the confusing wording. I should've been more clear. The "issue" I was referring to was in response to your question about if there was another reason for doubting the result. | |
| Dec 11, 2021 at 1:54 | comment | added | Michael E2 |
I don't know what "issue" you mean. The answers suggest the message comes from InterpolatingFunction when NMinimize steps outside the constraints. But the answer returned is within the constraints. So the step outside the constraint is rejected, and you can ignore the warning message.
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| Dec 11, 2021 at 1:24 | comment | added | mathemagician617 | @MichaelE2 I see what you're saying about NMinimize. Maybe my issue is coming from the interpolation functions. I'm not sure how to visualize anything that I'm doing so I haven't been able to visually check how the interpolating functions look or what the optimization results are. One thing that bothers me is that I get a different NMaximize result when I use order 3 for f1 interpolation vs order 2. | |
| Dec 11, 2021 at 0:59 | history | edited | Michael E2 |
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| Dec 11, 2021 at 0:58 | comment | added | Michael E2 |
The answers indicate that NMinimize can step outside the constraints, but eventually enforces them in the answer. When it steps outside the constraints, you get a InterpolatingFunction::dmval message. But if the answer is inside the constraints, then I doubt extrapolation has invalidated the answer. Is there some reason to doubt the result, other than the extrapolation warning?
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| Dec 11, 2021 at 0:32 | comment | added | mathemagician617 | @MichaelE2 Thank you for your response! I've been through those posts and I don't fully understand how I can use them to fix my problem. If you have any suggestions I would really appreciate it. Thank you! | |
| Dec 11, 2021 at 0:32 | history | edited | mathemagician617 | CC BY-SA 4.0 |
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| Dec 11, 2021 at 0:23 | comment | added | Michael E2 | Related/duplicate: mathematica.stackexchange.com/questions/42999/…, mathematica.stackexchange.com/questions/69622/… | |
| Dec 11, 2021 at 0:02 | history | edited | mathemagician617 | CC BY-SA 4.0 |
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| Dec 10, 2021 at 23:50 | history | asked | mathemagician617 | CC BY-SA 4.0 |