Grid Co-ordinates of Variables

Say I have two variables: u and p. ‘u’ is discretized by P2 and ‘p’ by P1.

Please see the following code:

mesh Th = square(10,10);
plot(Th, wait=1);

fespace femp1(Th,P1);
fespace femp2(Th,P2);

femp1 p; //p:=pressure
femp2 u; //u:=velocity

p = 3.7;
u = 5.4;

Doubt: How do I get the grid co-ordinates of the variables u and p (‘u’ is discretized by P2 and ‘p’ by P1)?

femp1 xc=x;
cout<<xc <<endl;

I thought this was odd but its a recurring paradigm in FF and handy
once you are used to it.