How to determine gauss point coordinates in a mesh

mesh
1

Hello fenics users,
I need to o determine gauss points coordinates of a mesh.
I’m a new fenics user, can any one helps me.
I will be grateful
Jihed ZGHAL

2

Maybe your are looking for this: How to get quadrature points and their weights? - #2 by bhaveshshrimali ?

3

Thank you for your quick reply. This exactly what I’m looking for. Based on the referred example I think that I can’t solve my problem.
I will explain more precisely my need: I generate this mesh as follow and I want to get the quadrature points :

print ( “Mesh Generation …” )

Structure dimension [mm]

L = 50
W = 10

Mesh size [mm]

h = 1
Nx = int( L/h ); print (" - number of element trough x direction = “, Nx);
Ny = int( W/h ); print (” - number of element trough y direction = ", Ny);
mesh = RectangleMesh(Point(-1*L, 0.), Point(L, W), Nx, Ny)
V = FunctionSpace(mesh, “CG”, 1)

Thank you for your help.

4

Do you want the physical quadrature points for each cell in your function space? These are automatically generated in ffc in fenics.

If you want to access them you could create a quadrature function space and tabulate the dof coordinates:

from dolfin import *

mesh = UnitSquareMesh(1, 1)
el = FiniteElement("Quadrature", mesh.ufl_cell(),  degree=2, quad_scheme="default")
V = FunctionSpace(mesh, el)
print(V.tabulate_dof_coordinates())

returning

[[ 0.83333333  0.66666667]
 [ 0.33333333  0.16666667]
 [ 0.83333333  0.16666667]
 [ 0.66666667  0.83333333]
 [ 0.16666667  0.33333333]
 [ 0.16666667  0.83333333]]
1 Like
5

thank you it’s exactly what I need.