Best integration method to integrate this oscilating function

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Lucas Pollito
Lucas Pollito on 26 Nov 2015
Answered: Josh Meyer on 9 Jul 2019
Hi. What method of integration, in matlab, should i use ? integral ? quadgk ? gausslegendre ?? any ideas ? this function oscilates a lot. I used trapz, but is was not a good idea
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Neekar Mohammed
Neekar Mohammed on 11 Jun 2019
Hi,
Did you find an answer for your problem?if you do please share it with us. I have the same problem.

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Answers (1)

Josh Meyer
Josh Meyer on 9 Jul 2019
integral can handle oscillatory integrands as long as there aren't too many oscillations, and you supply plenty of WayPoints in the difficult-to-evaluate areas. Think of this input as you telling the solver "these are the interesting areas you'll want to be aware of".
If that doesn't work, you should switch to using quadgk with the same waypoints, but also a large value for MaxIntervalCount. integral uses a large enough default value for MaxIntervalCount so that it rarely needs to be adjusted, but when it does, quadgk let's you make it as large as you want for really problematic integrands. If you don't make it large enough, quadgk will return a message instructing you how much larger to make MaxIntervalCount to complete another iteration.

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