Use of "periodic line" from gmsh in pygmsh

[chrissHugo]

Dear sirs,

I just hopped into gmsh and pygmsh. I try to enforce a periodic boundary condition on a 2D mesh (a square, constructed by 4 line elements).
The attached py-file combines the "raw code"-command from pygmsh with the "periodic line" command from gmsh. I got the error message:

'Unknown environment \'{}\'.'.format(environ)
 AssertionError: Unknown environment 'Periodic'.

I generated a quite similar geo file which I can mesh in gmsh directly without any Trouble.

Do you have any idea?

import pygmsh
import numpy as np
import meshio


geom = pygmsh.built_in.Geometry()

point_list = []

lcar = 0.1
p0 = geom.add_point([0.0, 0.0, 0.0], lcar)
p1 = geom.add_point([1.0, 0.0, 0.0], lcar)
p2 = geom.add_point([1.0, 1.0, 0.0], lcar)
p3 = geom.add_point([0.0, 1.0, 0.0], lcar)
# p4 = geom.add_point([1.0, 1.0, 0.0], lcar)

l0 = geom.add_line(p0, p1)
l1 = geom.add_line(p1, p2)
l2 = geom.add_line(p2, p3)
l3 = geom.add_line(p3, p0)
# l4 = geom.add_line(p4, p0)

ll = geom.add_line_loop([l0, l1, l2, l3])

surf = geom.add_plane_surface(ll)

geom.add_raw_code("Periodic Line {{ {0} }} = {{ {1} }};".format(l0.id, l2.id))

points, cells, point_data, cell_data, field_data = pygmsh.generate_mesh(geom)

meshio.write("test.msh", points, cells, cell_data=cell_data)

[nschloe]

This has been fixed in the meantime. Try

import pygmsh
import meshio

geom = pygmsh.built_in.Geometry()

point_list = []

lcar = 0.1
p0 = geom.add_point([0.0, 0.0, 0.0], lcar)
p1 = geom.add_point([1.0, 0.0, 0.0], lcar)
p2 = geom.add_point([1.0, 1.0, 0.0], lcar)
p3 = geom.add_point([0.0, 1.0, 0.0], lcar)
# p4 = geom.add_point([1.0, 1.0, 0.0], lcar)

l0 = geom.add_line(p0, p1)
l1 = geom.add_line(p1, p2)
l2 = geom.add_line(p2, p3)
l3 = geom.add_line(p3, p0)
# l4 = geom.add_line(p4, p0)

ll = geom.add_line_loop([l0, l1, l2, l3])

surf = geom.add_plane_surface(ll)

geom.add_raw_code("Periodic Curve {{{}}} = {{{}}};".format(l0.id, l2.id))

points, cells, point_data, cell_data, field_data = pygmsh.generate_mesh(geom, geo_filename="out.geo")

meshio.write_points_cells("test.msh", points, cells, cell_data=cell_data)