def from_vertices_and_etov(vertices, etov, flip = False):
vertex_objs = []
for v_idx in range(vertices.shape[0]):
vertex_objs.append(Vertex((vertices[v_idx, 0], vertices[v_idx, 1])))
element_objs = []
for e_idx in range(etov.shape[0]):
v0 = vertex_objs[etov[e_idx, 0]]
v1 = vertex_objs[etov[e_idx, 1]]
element_objs.append(Element(v0, v1))
if flip:
element_objs = correct_misorientation(element_objs)
m = Mesh(vertex_objs, element_objs)
apply_mapping(m, PolynomialMapping)
return m
def circular_mesh(n_elements, radius, mapping_gen = PolynomialMapping):
n_vertices = n_elements
t_list = np.linspace(0, 2 * np.pi, n_vertices + 1)[:-1]
circle_func = lambda t: (radius * np.cos(t), radius * np.sin(t))
x_list, y_list = circle_func(t_list)
vertices = []
for (x, y, t) in zip(x_list, y_list, t_list):
vertices.append(Vertex(np.array((x, y)), t))
elements = []
for i in range(0, n_elements - 1):
v0 = vertices[i]
v1 = vertices[i + 1]
elements.append(Element(v0, v1))
elements.append(Element(vertices[n_elements - 1], vertices[0]))
m = Mesh(vertices, elements)
apply_mapping(m, partial(mapping_gen, boundary_function = circle_func))
return m
def simple_line_mesh(n_elements,
left_edge = (-1.0, 0.0),
right_edge = (1.0, 0.0)):
"""
Create a mesh consisting of a line of elements starting at -1 and
extending to +1 in x coordinate, y = 0.
"""
n_vertices = n_elements + 1
x_list = np.linspace(left_edge[0], right_edge[0], n_vertices)
y_list = np.linspace(left_edge[1], right_edge[1], n_vertices)
vertices = []
for (x, y) in zip(x_list, y_list):
vertices.append(Vertex(np.array((x, y)), x))
elements = []
for i in range(0, n_elements):
v0 = vertices[i]
v1 = vertices[i + 1]
elements.append(Element(v0, v1))
m = Mesh(vertices, elements)
apply_mapping(m, PolynomialMapping)
return m
def ray_mesh(start_point, direction, length, flip = False):
"""
Create a mesh starting at start_point and going in the
direction specified with elements with a specified length.
This is a obviously linear mesh, so there is no point in adding the
necessary data to allow higher order mappings. This means that
higher order mappings will fail.
"""
# Convert to numpy arrays so that users don't have to.
start_point = np.array(start_point)
direction = np.array(direction)
# Normalize direction so the lengths stay true.
direction /= np.linalg.norm(direction)
vertices = []
vertices.append(Vertex(np.array(start_point)))
sum_l = 0
for l in length:
sum_l += l
new_point = start_point + sum_l * direction
vertices.append(Vertex(new_point))
if flip:
vertices.reverse()
elements = []
for i in range(0, len(length)):
v0 = vertices[i]
v1 = vertices[i + 1]
# if flip:
# v0, v1 = v1, v0
elements.append(Element(v0, v1))
# if flip:
# elements.reverse()
m = Mesh(vertices, elements)
apply_mapping(m, PolynomialMapping)
return m
