def _fill_mesh_bdr_elements(omesh, vtx, bindices, nbverts, battrs, bbase,
kbelem):
cnbverts = np.hstack([0, np.cumsum(nbverts)])
for i, ba in enumerate(battrs):
if not kbelem[i]:
print("skipping")
continue
iv = bindices[cnbverts[i]:cnbverts[i + 1]]
if bbase[i] == 0:
el = mfem.Point(iv[0])
el.SetAttribute(ba)
el.thisown = False
omesh.AddBdrElement(el)
elif bbase[i] == 1:
omesh.AddBdrSegment(list(iv), ba)
elif bbase[i] == 2:
#if myid == 1: print(list(iv), ba)
omesh.AddBdrTriangle(list(iv), ba)
elif bbase[i] == 3:
omesh.AddBdrQuad(list(iv), ba)
else:
assert False, "unsupported base geometry: " + str(bbase[i])
for v in vtx:
omesh.AddVertex(list(v))
def straight_line_mesh(lengths,
nsegs,
filename='',
refine=False,
fix_orientation=False,
sdim=3,
x0=0.0):
Nvert = np.sum(nsegs) + 1
Nelem = np.sum(nsegs)
Nbdrelem = len(lengths) + 1
mesh = mfem.Mesh(1, Nvert, Nelem, Nbdrelem, sdim)
ivert = {}
L = np.hstack(([0], np.cumsum(lengths))).astype(float)
P = np.hstack(([0], np.cumsum(nsegs))).astype(int)
X = [np.linspace(L[i], L[i + 1], n + 1)[1:] for i, n in enumerate(nsegs)]
X = np.hstack(([0], np.hstack(X)))
A = np.hstack([[i + 1] * n for i, n in enumerate(nsegs)])
for k, i in enumerate(P):
ptx = mfem.Point(i)
ptx.SetAttribute(k + 1)
mesh.AddBdrElement(ptx)
ptx.thisown = False
for i in range(X.shape[0] - 1):
seg = mfem.Segment((i, i + 1), A[i])
mesh.AddElement(seg)
seg.thisown = False
for i in range(X.shape[0]):
pt = [0] * sdim
pt[0] = X[i] + x0
mesh.AddVertex(pt)
mesh.FinalizeTopology()
mesh.Finalize(refine, fix_orientation)
if filename != '':
mesh.PrintToFile(filename, 8)
return mesh