# Plot in 3d with .vtu and paraview

**URL:** <https://community.freefem.org/t/plot-in-3d-with-vtu-and-paraview/57>\
**Category:** General Discussion\
**Created:** [May 24, 2019, 5:35pm UTC](https://community.freefem.org/t/plot-in-3d-with-vtu-and-paraview/57 "2019-05-24T17:35:30Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Aicha](https://avatars.discourse-cdn.com/v4/letter/a/ec9cab/32.png) [@Aicha](https://community.freefem.org/u/Aicha)\
**Post date:** [May 24, 2019, 5:35pm UTC](https://community.freefem.org/t/plot-in-3d-with-vtu-and-paraview/57/1 "2019-05-24T17:35:30Z")

</div>

Hi

i have to plot the Following function:

q(x/eps,y/eps,z/eps)=1 if (x/eps,y/eps,z/eps) \in B\_{\delta}+ Z^3, else 0.

where B\_{delta} is the ball with radius

\delta= ((3/4)_(1/(w_pi)))^{1/3}

we choise eps=0.1 and w=2000.

The problem is that in .vtu we Don’t ditingue the ball when q=1 to the rest when q=0.

I search in the doc but i Don’t find how we save .vtu in 3d (i choice 3d in paraview). So there is an solution?

And the image after copilation Don’t show the ball.

Thank you in advance to the help. There is the code:

’ ’ ’ freefem  
load “UMFPACK64”  
defaulttoUMFPACK64();

load “iovtk”

load “msh3”

verbosity=1;

func real q (real t, real s, real c,real w) {  
real t1 = t - rint(t);  
real s1 = s - rint(s);  
real c1 = c -rint©;  
real delta= ((3./4.)_(1./(pi_w)))^(1/3);  
if ( square(s1)+square(t1)+square(c1) \<= square(delta))  
return 1;  
else  
return 0.0;  
};  
real eps=0.2, w=2000.;

mesh3 Th=cube(30,30,30);  
fespace Wh(Th,P2,periodic=[[1,x,z],[3,x,z],[2,y,z],[4,y,z],[5,x,y],[6,x,y]]);  
Wh uplot;  
int[int] Order= [1];

uplot=q(x/eps,y/eps,z/eps,w);  
plot(uplot,wait=1,dim=3);  
savevtk(“q.vtu”,Th,uplot,dataname=“qdelta”, order=Order);

Kind regards