# Default quadrature rule

**URL:** <https://community.freefem.org/t/default-quadrature-rule/415>\
**Category:** General Discussion\
**Created:** [May 16, 2020, 11:23am UTC](https://community.freefem.org/t/default-quadrature-rule/415 "2020-05-16T11:23:20Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![BeniaminBogosel](https://avatars.discourse-cdn.com/v4/letter/b/3ec8ea/32.png) [@BeniaminBogosel](https://community.freefem.org/u/BeniaminBogosel)\
**Post date:** [May 16, 2020, 11:23am UTC](https://community.freefem.org/t/default-quadrature-rule/415/1 "2020-05-16T11:23:20Z")

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Hello,

I have a question about the default choice of quadrature in FreeFEM. Does FreeFEM choose the default quadrature rule to be of highest degree that is exact for the corresponding finite element function? Or do we need to change it by hand looking at the documentation for P2, P3 elements?

Thank you, Beniamin

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**Author:** ![prj](https://avatars.discourse-cdn.com/v4/letter/p/ecae2f/32.png) [@prj](https://community.freefem.org/u/prj)\
**Post date:** [May 16, 2020, 11:35am UTC](https://community.freefem.org/t/default-quadrature-rule/415/2 "2020-05-16T11:35:15Z")

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You need to set it appropriately. E.g., if you compute `int2d(Th)(u*v)` with `u` and `v` of type `P4`, you’ll get incorrect results, unless you use the appropriate `qforder`.

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**Author:** ![BeniaminBogosel](https://avatars.discourse-cdn.com/v4/letter/b/3ec8ea/32.png) [@BeniaminBogosel](https://community.freefem.org/u/BeniaminBogosel)\
**Post date:** [May 16, 2020, 12:28pm UTC](https://community.freefem.org/t/default-quadrature-rule/415/3 "2020-05-16T12:28:28Z")

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Thank you for your answer! I think I got it now.

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**Author:** ![quentin](https://avatars.discourse-cdn.com/v4/letter/q/e47c2d/32.png) [@quentin](https://community.freefem.org/u/quentin)\
**Post date:** [May 19, 2025, 8:08am UTC](https://community.freefem.org/t/default-quadrature-rule/415/4 "2025-05-19T08:08:27Z")

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In the FreeFEM documentation, `qforder=6` is exact on `P5`:

 ![image](https://canada1.discourse-cdn.com/flex030/uploads/freefem/original/2X/0/0702120674fa5b8432d615595f9bba7271643f91.png)  
While I do not get a correct result on `P4` until `qforder=7`. I am a bit confused.
