# How i can programming this term

**URL:** <https://community.freefem.org/t/how-i-can-programming-this-term/184>\
**Category:** General Discussion\
**Created:** [November 22, 2019, 10:25pm UTC](https://community.freefem.org/t/how-i-can-programming-this-term/184 "2019-11-22T22:25:10Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![sellila](https://avatars.discourse-cdn.com/v4/letter/s/c67d28/32.png) [@sellila](https://community.freefem.org/u/sellila)\
**Post date:** [November 22, 2019, 10:25pm UTC](https://community.freefem.org/t/how-i-can-programming-this-term/184/1 "2019-11-22T22:25:10Z")

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Hello everyone, i need help because, i am begineer in Freefem++  
There are someone can help me, how i can programming this term

a|u|^{\alpha}u

where |u| is the norm on the unknown function  
|u| = sqrt(ux^² + uy)  
Thank you

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**Author:** ![iftikhar](https://avatars.discourse-cdn.com/v4/letter/i/cab0a1/32.png) [@iftikhar](https://community.freefem.org/u/iftikhar)\
**Post date:** [November 23, 2019, 5:59am UTC](https://community.freefem.org/t/how-i-can-programming-this-term/184/2 "2019-11-23T05:59:30Z")

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The L\_2 norm of a vector u is defined as |u| = (\int\_{\Omega} u\*u d{\Omega))^{1/2}.  
You can calculate it as follows (I assume that you are working in finite element space and  
have a mesh on your domain in 2D).  
|u| = sqrt(int2d(Th)(u\*u))

Cheers

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**Author:** ![sellila](https://avatars.discourse-cdn.com/v4/letter/s/c67d28/32.png) [@sellila](https://community.freefem.org/u/sellila)\
**Post date:** [November 23, 2019, 7:17pm UTC](https://community.freefem.org/t/how-i-can-programming-this-term/184/3 "2019-11-23T19:17:23Z")

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Thank you so much,  
yes, i work in Finite Element space and the domain 2D.