# Get labels of boundary nodes for P2 elements

**URL:** https://community.freefem.org/t/get-labels-of-boundary-nodes-for-p2-elements/471
**Category:** General Discussion
**Created:** [June 15, 2020, 11:04am UTC](https://community.freefem.org/t/get-labels-of-boundary-nodes-for-p2-elements/471 "2020-06-15T11:04:58Z")
**Posts on this page:** 1
**Showing post:** 7

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### Author: ![frederichecht](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/frederichecht/32/15_2.png) [@frederichecht](https://community.freefem.org/u/frederichecht)
#### Post date: [June 16, 2020, 10:11am UTC](https://community.freefem.org/t/get-labels-of-boundary-nodes-for-p2-elements/471/7 "2020-06-16T10:11:59Z")

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This is a little bit more complexe because a node could be on more the 1 boundary (corner ponts  
for examples).

```
mesh Th=square (10,10);
fespace Vh(Th,P2);

Vh l2 = label;
plot(l2, wait=1);

// it is correct expect on corner ..

// border l;
for(int l=1; l<=4; ++l)
{
varf vb1(u,v)= on(l,u=1);
Vh l1;
l1[] = vb1(0,Vh,tgv=1);// 1 on l border ..
plot(l1,wait=1,cmm=" border l="+l);
}
```

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