13-Aquamarine

Solved

Apparent Error in Simple Integral with Prime 7

Forum|Forum|5 years ago
March 24, 2021
2 replies
6527 views

Hi Folks,

I just got Prime 7 and tried to do a sample calculation for a class. It doesn't seem to be able to evaluate a very simple integral. V15 and MATLAB both get the right answer with no problem. The weird part is that it only gives the wrong answer when the number is 4. I didn't see a problem with other numbers. This was for a lesson on Fourier series.

Hopefully, the problem is me and not Prime 7. I most appreciate any suggestions.

Mark

Best answer by rgunwaldsen

Bummer. Opened case Case 15810622. Cannot trust numerical calculations?

23-Emerald IV

I'm sorry, but the problem is not you, but Prime 7.

Better stick with Prime 6, where it was still OK:

Which means that PTC (again) managed to make things worse.

But it does get better in Prime 7 when you split the integral up:

And then it doesn't matter how you split it up:

If you're a licensed user, report this serious bug to PTC.

Luc

Answer

15-Moonstone

Bummer. Opened case Case 15810622. Cannot trust numerical calculations?

Author

13-Aquamarine

Thanks for opening the case. I'm surprised that Prime would have an error like this after such a long development.

Mark

21-Topaz II

mfrench answer.jpg

1_six-pulse-trains.zip

Author

13-Aquamarine

Thanks for the example. It appears to work as a symbolic calculation in Prime 7, but not a numerical one?

Mark

21-Topaz II

Another oddity:

mfrench answer 1.jpg