def test_add_element(self):
mesh = Mesh(2)
for nodeid, coords in zip(self._nodeids, self._nodes):
mesh.add_node(coords, nodeid)
conn_desired = np.array([5, 6, 3], dtype=np.int)
shape_desired = 'Tri3'
new_id = mesh.add_element(shape_desired, conn_desired)
shape_actual = mesh.get_ele_shapes_by_elementids([new_id])[0]
conn_actual = mesh.get_connectivity_by_elementids([new_id])[0]
self.assertEqual(shape_actual, shape_desired)
assert_array_equal(conn_actual, conn_desired)
conn_desired = np.array([4, 1], dtype=np.int)
shape_desired = 'straight_line'
new_id = mesh.add_element(shape_desired, conn_desired)
shape_actual = mesh.get_ele_shapes_by_elementids([new_id])[0]
conn_actual = mesh.get_connectivity_by_elementids([new_id])[0]
self.assertEqual(shape_actual, shape_desired)
assert_array_equal(conn_actual, conn_desired)
conn_desired = np.array([3, 2, 5], dtype=np.int)
shape_desired = 'Tri3'
new_id = mesh.add_element(shape_desired,
np.array([3, 2, 5], dtype=np.int), 5)
shape_actual = mesh.get_ele_shapes_by_elementids([new_id])[0]
conn_actual = mesh.get_connectivity_by_elementids([new_id])[0]
self.assertEqual(shape_actual, shape_desired)
assert_array_equal(conn_actual, conn_desired)
self.assertEqual(new_id, 5)
with self.assertRaises(ValueError):
mesh.add_element('Quad4', np.array([1, 2, 3, 4], dtype=np.int), 5)
conn_desired = np.array([1, 2, 3, 4], dtype=np.int)
shape_desired = 'Quad4'
new_id = mesh.add_element('Quad4',
np.array([1, 2, 3, 4], dtype=np.int),
5,
overwrite=True)
shape_actual = mesh.get_ele_shapes_by_elementids([new_id])[0]
conn_actual = mesh.get_connectivity_by_elementids([new_id])[0]
self.assertEqual(shape_actual, shape_desired)
assert_array_equal(conn_actual, conn_desired)
self.assertEqual(new_id, 5)
# Test wrong dtype
new_id = mesh.add_element('Quad4',
np.array([1, 2, 3, 4], dtype=np.float), 6)
shape_actual = mesh.get_ele_shapes_by_elementids([new_id])[0]
conn_actual = mesh.get_connectivity_by_elementids([new_id])[0]
self.assertEqual(shape_actual, shape_desired)
assert_array_equal(conn_actual, conn_desired)
self.assertEqual(new_id, 6)
# Test with tuple instead of array
new_id = mesh.add_element('Quad4', (1, 2, 3, 4), 7)
shape_actual = mesh.get_ele_shapes_by_elementids([new_id])[0]
conn_actual = mesh.get_connectivity_by_elementids([new_id])[0]
self.assertEqual(shape_actual, shape_desired)
assert_array_equal(conn_actual, conn_desired)
self.assertEqual(new_id, 7)
# Test wrong shape
with self.assertRaises(ValueError):
mesh.add_element('wrong_shape', np.array([1, 2, 3, 4],
dtype=np.int), 8)
class RectangleMesh2D:
def __init__(self, l, h, n_ele_l, n_ele_h, x_start=0.0, y_start=0.0):
self.l = l
self.h = h
self.n_ele_l = n_ele_l
self.n_ele_h = n_ele_h
self.delta_h_x = self.l / self.n_ele_l
self.delta_h_y = self.h / self.n_ele_h
self.x_start = x_start
self.y_start = y_start
self._mesh = Mesh(2)
@property
def mesh(self):
return self._mesh
def generate_mesh(self):
self._create_nodes()
self._create_elements()
def _create_nodes(self):
for i_node_y in np.arange(self.n_ele_h+1):
for i_node_x in np.arange(self.n_ele_l+1):
self._mesh.add_node([self.x_start + i_node_x * self.delta_h_x, self.y_start + i_node_y * self.delta_h_y])
def _create_elements(self):
for i_ele_y in np.arange(self.n_ele_h):
for i_ele_x in np.arange(self.n_ele_l):
node1 = self._mesh.get_nodeid_by_coordinates(self.x_start + i_ele_x * self.delta_h_x,
self.y_start + i_ele_y * self.delta_h_y)
node2 = self._mesh.get_nodeid_by_coordinates(self.x_start + (i_ele_x + 1) * self.delta_h_x,
self.y_start + i_ele_y * self.delta_h_y)
node3 = self._mesh.get_nodeid_by_coordinates(self.x_start + (i_ele_x + 1) * self.delta_h_x,
self.y_start + (i_ele_y + 1) * self.delta_h_y)
node4 = self._mesh.get_nodeid_by_coordinates(self.x_start + i_ele_x * self.delta_h_x,
self.y_start + (i_ele_y + 1) * self.delta_h_y)
connectivity = np.array([node1, node2, node3, node4])
self._mesh.add_element('Quad4', connectivity)
def add_boundary(self, edge, group_name=None):
if edge is 'left':
nodes = self._mesh.get_nodeids_by_coordinate_axis(self.x_start, 'x', 1e-6)
elif edge is 'right':
nodes = self._mesh.get_nodeids_by_coordinate_axis(self.x_start+self.l, 'x', 1e-6)
elif edge is 'bottom':
nodes = self._mesh.get_nodeids_by_coordinate_axis(self.y_start, 'y', 1e-6)
elif edge is 'top':
nodes = self._mesh.get_nodeids_by_coordinate_axis(self.y_start + self.h, 'y', 1e-6)
else:
raise ValueError('Unknown edge-type')
for idx in range(nodes.size-1):
eleid = self._mesh.add_element('straight_line', np.array([nodes[idx], nodes[idx+1]]))
if group_name is not None and len(self._mesh.get_groups_by_elementids([eleid])) == 0:
if group_name in self._mesh.groups:
self._mesh.add_element_to_groups(eleid, [group_name])
else:
self._mesh.create_group(group_name, (), [eleid])
def set_checkerboard_groups(self, segment_length, segment_height, segment_groups):
n_seg_x = int(round(self.l/segment_length))
n_seg_y = int(round(self.h/segment_height))
segments = dict()
seg = 0
for seg_y in range(n_seg_y):
for seg_x in range(n_seg_x):
if seg_y % 2 == 0:
group_name = segment_groups[seg_x % len(segment_groups)]
else:
group_name = segment_groups[(seg_x+1) % len(segment_groups)]
segments[seg] = {'nodes': {'lowerleft': np.array([seg_x * segment_length, seg_y * segment_height]),
'lowerright': np.array([(seg_x + 1) * segment_length, seg_y * segment_height]),
'upperleft': np.array([seg_x * segment_length, (seg_y + 1) * segment_height]),
'upperright': np.array([(seg_x + 1) * segment_length, (seg_y + 1) * segment_height])},
'group': group_name
}
seg += 1
def check_node_in_segment(P1, P2, P3, P4, node):
edge_x = P2 - P1
edge_y = P4 - P1
constraint_x = (np.dot(edge_x, P1) <= np.dot(edge_x, node) <= np.dot(edge_x, P2))
constraint_y = (np.dot(edge_y, P1) <= np.dot(edge_y, node) <= np.dot(edge_y, P4))
return constraint_x and constraint_y
eleids = self._mesh.get_elementids_by_tags(['shape'], ['Quad4'])
for eleid in eleids:
nodes = self._mesh.get_nodeids_by_elementids([eleid])
for idx, seg in segments.items():
seg_nodes = seg['nodes']
ele_in_segment = True
for node in nodes:
node_pos = np.array([self._mesh.nodes_df.at[node,'x'], self._mesh.nodes_df.at[node,'y']])
if not check_node_in_segment(seg_nodes['lowerleft'], seg_nodes['lowerright'],
seg_nodes['upperright'], seg_nodes['upperleft'], node_pos):
ele_in_segment = False
break
if ele_in_segment:
if seg['group'] in self._mesh.groups:
self._mesh.add_element_to_groups(eleid, [seg['group']])
else:
self._mesh.create_group(seg['group'], (), [eleid])
break
def set_homogeneous_group(self, groupname):
self._mesh.create_group(groupname, (), self._mesh.get_elementids_by_tags(['shape'], ['Quad4']))