Voropy throws AssertionError about pygmsh

[nschloe]

You could set num_lloyd_steps to 0, that'll probably help.

Interesting that this fails though. Could you generate a small example that reproduces the error and post it here?

[MuellerSeb]

import pygmsh as pg
from pygmsh.built_in import Geometry


def gmsh_grid_adapt2D(out_dim=(100., 100.),
                      in_dim=(50., 50.),
                      out_res=(10., 10.),
                      in_res=(5., 5.),
                      out_pos=(0., 0.),
                      in_pos=(25., 25.),
                      z_pos=0.):
    '''
    Generate the 2D mesh adapter.
    '''
    geo = Geometry()
    code = [
        # "// size of the outer block",
        "outx = {};".format(out_dim[0]),
        "outy = {};".format(out_dim[1]),
        # "// size of the inner block",
        "inx = {};".format(in_dim[0]),
        "iny = {};".format(in_dim[1]),
        # "// outer grid resolution",
        "grioutx = {};".format(out_res[0]),
        "griouty = {};".format(out_res[1]),
        # "// inner grid resolution",
        "grix = {};".format(in_res[0]),
        "griy = {};".format(in_res[1]),
        # "// position of the outer block",
        "obx = {};".format(out_pos[0]),
        "oby = {};".format(out_pos[1]),
        # "// position of the inner block",
        "ibx = {};".format(in_pos[0]),
        "iby = {};".format(in_pos[1]),
        # "// z-position of the block",
        "bz = {};".format(z_pos),
        # "// outer block points",
        "Point(1) = {obx,       oby,        bz,         grioutx};",
        "Point(2) = {obx+outx,  oby,        bz,         grioutx};",
        "Point(3) = {obx+outx,  oby+outy,   bz,         grioutx};",
        "Point(4) = {obx,       oby+outy,   bz,         grioutx};",
        # "// inner block points",
        "Point(9) =  {ibx,      iby,        bz,         grix};",
        "Point(10) = {ibx+inx,  iby,        bz,         grix};",
        "Point(11) = {ibx+inx,  iby+iny,    bz,         grix};",
        "Point(12) = {ibx,      iby+iny,    bz,         grix};",
        # "// outer block lines",
        "Line(1) = {1, 2}; //s top",
        "Line(2) = {2, 3}; //e top",
        "Line(3) = {3, 4}; //n top",
        "Line(4) = {4, 1}; //w top",
        # "// inner block lines",
        "Line(13) = {9, 10}; //s top",
        "Line(14) = {10, 11}; //e top",
        "Line(15) = {11, 12}; //n top",
        "Line(16) = {12, 9}; //w top",
        # "// top surface",
        "Line Loop(26) = {1, 2, 3, 4};",
        "Line Loop(27) = {13, 14, 15, 16};",
        "Plane Surface(28) = {26, 27};",
        # "// make the outer sides rectengular",
        "Transfinite Line{1, 3} = outx/grioutx + 1;",
        "Transfinite Line{2, 4} = outy/griouty + 1;",
        # "// make the inner sides rectengular",
        "Transfinite Line{13, 15} = inx/grix + 1;",
        "Transfinite Line{14, 16} = iny/griy + 1;"]
    geo.add_raw_code(code)
    return geo

testgeo = gmsh_grid_adapt2D()

points, cells, __, __, __ = pg.generate_mesh(testgeo,
                                             num_lloyd_steps=0,
                                             dim=2)

[MuellerSeb]

"You could set num_lloyd_steps to 0" ... didn't help for me. I get the same Error as before.

[nschloe]

Ah. This is a failure in gmsh itself. Try setting num_quad_lloyd_steps to 0.

[nschloe]

Explanation: There is

• "quad Lloyd" from gmsh (which puts the cells in a "quad"-type mesh) and
• (actual) Lloyd from voropy.

[MuellerSeb]

"Try setting num_quad_lloyd_steps to 0" ... still throws the same Error. Does it work for you with the example from above?

[MuellerSeb]

My suggestion would be to replace the lines 147-158 in helpers.py with:

    if num_lloyd_steps > 0:
        if verbose:
            print('Lloyd smoothing...')
        # find submeshes
        a = cell_data['triangle']['geometrical']
        # http://stackoverflow.com/q/42740483/353337
        submesh_bools = {v: v == a for v in numpy.unique(a)}

        X, cells['triangle'] = voropy.smoothing.lloyd_submesh(
                X, cells['triangle'], submesh_bools,
                tol=0.0, max_steps=num_lloyd_steps,
                verbose=False
                )

that solves the problem for me ;)

[nschloe]

Then that's the way we'll do it. I just released 4.0.3 with your proposed change.