def create_square_element(mesh: Mesh, finite_element_field: Field,
node_coordinate_set):
"""
Create a single square 2-D finite element using the supplied
finite element field and sequence of 4 n-D node coordinates.
:param mesh: The Zinc Mesh to create elements in.
:param finite_element_field: Zinc FieldFiniteElement to interpolate on element.
:param node_coordinate_set: Sequence of 4 coordinates each with as many components as finite element field.
:return: None
"""
assert mesh.getDimension() == 2
assert finite_element_field.castFiniteElement().isValid()
assert len(node_coordinate_set) == 4
fieldmodule = finite_element_field.getFieldmodule()
nodeset = fieldmodule.findNodesetByFieldDomainType(Field.DOMAIN_TYPE_NODES)
node_template = nodeset.createNodetemplate()
node_template.defineField(finite_element_field)
element_template = mesh.createElementtemplate()
element_template.setElementShapeType(Element.SHAPE_TYPE_SQUARE)
linear_basis = fieldmodule.createElementbasis(
2, Elementbasis.FUNCTION_TYPE_LINEAR_LAGRANGE)
eft = mesh.createElementfieldtemplate(linear_basis)
element_template.defineField(finite_element_field, -1, eft)
field_cache = fieldmodule.createFieldcache()
with ChangeManager(fieldmodule):
node_identifiers = []
for node_coordinate in node_coordinate_set:
node = nodeset.createNode(-1, node_template)
node_identifiers.append(node.getIdentifier())
field_cache.setNode(node)
finite_element_field.assignReal(field_cache, node_coordinate)
element = mesh.createElement(-1, element_template)
element.setNodesByIdentifier(eft, node_identifiers)
fieldmodule.defineAllFaces()
def create_fields_transformations(coordinates: Field,
rotation_angles=None,
scale_value=1.0,
translation_offsets=None):
"""
Create constant fields for rotation, scale and translation containing the supplied
values, plus the transformed coordinates applying them in the supplied order.
:param coordinates: The coordinate field to scale, 3 components.
:param rotation_angles: List of euler angles, length = number of components.
See create_field_euler_angles_rotation_matrix.
:param scale_value: Scalar to multiply all components of coordinates.
:param translation_offsets: List of offsets, length = number of components.
:return: 4 fields: transformedCoordinates, rotation, scale, translation
"""
if rotation_angles is None:
rotation_angles = [0.0, 0.0, 0.0]
if translation_offsets is None:
translation_offsets = [0.0, 0.0, 0.0]
components_count = coordinates.getNumberOfComponents()
assert (components_count == 3) and (len(rotation_angles) == components_count) and isinstance(scale_value, float) \
and (len(translation_offsets) == components_count), "createTransformationFields. Invalid arguments"
fieldmodule = coordinates.getFieldmodule()
with ChangeManager(fieldmodule):
# scale, translate and rotate model, in that order
rotation = fieldmodule.createFieldConstant(rotation_angles)
scale = fieldmodule.createFieldConstant(scale_value)
translation = fieldmodule.createFieldConstant(translation_offsets)
rotation_matrix = create_field_euler_angles_rotation_matrix(
fieldmodule, rotation)
rotated_coordinates = fieldmodule.createFieldMatrixMultiply(
components_count, rotation_matrix, coordinates)
transformed_coordinates = rotated_coordinates * scale + translation
assert transformed_coordinates.isValid()
return transformed_coordinates, rotation, scale, translation
def createFieldsTransformations(coordinates: Field, rotation_angles=None, scale_value=1.0, \
translation_offsets=None, translation_scale_factor=1.0):
"""
Create constant fields for rotation, scale and translation containing the supplied
values, plus the transformed coordinates applying them in the supplied order.
:param coordinates: The coordinate field to scale, 3 components.
:param rotation_angles: List of euler angles, length = number of components.
See create_field_euler_angles_rotation_matrix.
:param scale_value: Scalar to multiply all components of coordinates.
:param translation_offsets: List of offsets, length = number of components.
:param translation_scale_factor: Scaling to multiply translation by so it's magnitude can remain
close to other parameters for rotation (radians) and scale (assumed close to unit).
:return: 4 fields: transformedCoordinates, rotation, scale, translation
"""
if rotation_angles is None:
rotation_angles = [0.0, 0.0, 0.0]
if translation_offsets is None:
translation_offsets = [0.0, 0.0, 0.0]
components_count = coordinates.getNumberOfComponents()
assert (components_count == 3) and (len(rotation_angles) == components_count) and isinstance(scale_value, float) \
and (len(translation_offsets) == components_count), "createFieldsTransformations. Invalid arguments"
fieldmodule = coordinates.getFieldmodule()
with ChangeManager(fieldmodule):
# Rotate, scale, and translate model, in that order
rotation = fieldmodule.createFieldConstant(rotation_angles)
scale = fieldmodule.createFieldConstant(scale_value)
translation = fieldmodule.createFieldConstant(translation_offsets)
rotation_matrix = create_field_euler_angles_rotation_matrix(
fieldmodule, rotation)
rotated_coordinates = fieldmodule.createFieldMatrixMultiply(
components_count, rotation_matrix, coordinates)
transformed_coordinates = rotated_coordinates*scale + (translation if (translation_scale_factor == 1.0) else \
translation*fieldmodule.createFieldConstant([ translation_scale_factor ]*components_count))
assert transformed_coordinates.isValid()
return transformed_coordinates, rotation, scale, translation
def create_field_mesh_integral(coordinates: Field, mesh: Mesh, number_of_points=3):
"""
Create a field integrating the coordinates to give scalar volume/area/length over
the mesh, depending on its dimension.
:param coordinates:
:param mesh:
:param number_of_points: Number of Gauss points.
:return: Field giving volume of coordinates field over mesh via Gaussian quadrature.
"""
fieldmodule = coordinates.getFieldmodule()
with ChangeManager(fieldmodule):
mesh_integral_field = fieldmodule.createFieldMeshIntegral(fieldmodule.createFieldConstant(1.0),
coordinates, mesh)
mesh_integral_field.setNumbersOfPoints(number_of_points)
return mesh_integral_field
def getNodesetConditionalSize(nodeset: Nodeset, conditionalField: Field):
"""
:return: Number of objects in nodeset for which conditionalField is True.
"""
assert conditionalField.getNumberOfComponents() == 1
fieldmodule = conditionalField.getFieldmodule()
fieldcache = fieldmodule.createFieldcache()
nodeiterator = nodeset.createNodeiterator()
size = 0
node = nodeiterator.next()
while node.isValid():
fieldcache.setNode(node)
result, value = conditionalField.evaluateReal(fieldcache, 1)
if value != 0.0:
size += 1
node = nodeiterator.next()
return size
def create_field_finite_element_clone(source_field: Field,
name: str,
managed=False) -> FieldFiniteElement:
"""
Copy an existing Finite Element Field to a new field of supplied name.
Note: does not handle time-varying parameters.
New field is not managed by default.
:param source_field: Zinc finite element field to copy.
:param name: The name of the new field, asserts that no field of that name exists.
:param managed: Managed state of field created here.
:return: New identically defined field with supplied name.
"""
assert source_field.castFiniteElement().isValid(), \
"opencmiss.utils.zinc.field.createFieldFiniteElementClone. Not a Zinc finite element field"
fieldmodule = source_field.getFieldmodule()
field = fieldmodule.findFieldByName(name)
assert not field.isValid(
), "opencmiss.utils.zinc.field.createFieldFiniteElementClone. Target field name is in use"
with ChangeManager(fieldmodule):
# Zinc needs a function to do this efficiently; currently serialise to string, replace field name and reload!
source_name = source_field.getName()
region = fieldmodule.getRegion()
sir = region.createStreaminformationRegion()
srm = sir.createStreamresourceMemory()
sir.setFieldNames([source_name])
region.write(sir)
result, buffer = srm.getBuffer()
# small risk of modifying other text here:
source_bytes = bytes(") " + source_name + ",", "utf-8")
target_bytes = bytes(") " + name + ",", "utf-8")
buffer = buffer.replace(source_bytes, target_bytes)
sir = region.createStreaminformationRegion()
sir.createStreamresourceMemoryBuffer(buffer)
result = region.read(sir)
assert result == RESULT_OK
# note currently must have called endChange before field can be found
field = fieldmodule.findFieldByName(name).castFiniteElement()
field.setManaged(managed)
assert field.isValid()
return field
def create_triangle_elements(mesh: Mesh, finite_element_field: Field,
element_node_set):
"""
Create a linear triangular element for every set of 3 local nodes in element_node_set.
:param mesh: The Zinc Mesh to create elements in.
:param finite_element_field: Zinc FieldFiniteElement to interpolate from nodes.
:param element_node_set: Sequence of 3 node identifiers for each element.
:return: None
"""
assert mesh.getDimension() == 2
assert finite_element_field.castFiniteElement().isValid()
fieldmodule = finite_element_field.getFieldmodule()
element_template = mesh.createElementtemplate()
element_template.setElementShapeType(Element.SHAPE_TYPE_TRIANGLE)
linear_basis = fieldmodule.createElementbasis(
2, Elementbasis.FUNCTION_TYPE_LINEAR_SIMPLEX)
eft = mesh.createElementfieldtemplate(linear_basis)
element_template.defineField(finite_element_field, -1, eft)
with ChangeManager(fieldmodule):
for element_nodes in element_node_set:
element = mesh.createElement(-1, element_template)
element.setNodesByIdentifier(eft, element_nodes)
fieldmodule.defineAllFaces()
def transform_coordinates(field: Field,
rotation_scale,
offset,
time=0.0) -> bool:
"""
Transform finite element field coordinates by matrix and offset, handling nodal derivatives and versions.
Limited to nodal parameters, rectangular cartesian coordinates
:param field: the coordinate field to transform
:param rotation_scale: square transformation matrix 2-D array with as many rows and columns as field components.
:param offset: coordinates offset.
:param time: time value.
:return: True on success, otherwise false.
"""
ncomp = field.getNumberOfComponents()
if (ncomp != 2) and (ncomp != 3):
print(
'zinc.transformCoordinates: field has invalid number of components'
)
return False
if (len(rotation_scale) != ncomp) or (len(offset) != ncomp):
print(
'zinc.transformCoordinates: invalid matrix number of columns or offset size'
)
return False
for matRow in rotation_scale:
if len(matRow) != ncomp:
print(
'zinc.transformCoordinates: invalid matrix number of columns')
return False
if field.getCoordinateSystemType(
) != Field.COORDINATE_SYSTEM_TYPE_RECTANGULAR_CARTESIAN:
print('zinc.transformCoordinates: field is not rectangular cartesian')
return False
fe_field = field.castFiniteElement()
if not fe_field.isValid():
print(
'zinc.transformCoordinates: field is not finite element field type'
)
return False
success = True
fm = field.getFieldmodule()
fm.beginChange()
cache = fm.createFieldcache()
cache.setTime(time)
nodes = fm.findNodesetByFieldDomainType(Field.DOMAIN_TYPE_NODES)
node_template = nodes.createNodetemplate()
node_iter = nodes.createNodeiterator()
node = node_iter.next()
while node.isValid():
node_template.defineFieldFromNode(fe_field, node)
cache.setNode(node)
for derivative in [
Node.VALUE_LABEL_VALUE, Node.VALUE_LABEL_D_DS1,
Node.VALUE_LABEL_D_DS2, Node.VALUE_LABEL_D2_DS1DS2,
Node.VALUE_LABEL_D_DS3, Node.VALUE_LABEL_D2_DS1DS3,
Node.VALUE_LABEL_D2_DS2DS3, Node.VALUE_LABEL_D3_DS1DS2DS3
]:
versions = node_template.getValueNumberOfVersions(
fe_field, -1, derivative)
for v in range(versions):
result, values = fe_field.getNodeParameters(
cache, -1, derivative, v + 1, ncomp)
if result != RESULT_OK:
success = False
else:
new_values = vectorops.matrixvectormult(
rotation_scale, values)
if derivative == Node.VALUE_LABEL_VALUE:
new_values = vectorops.add(new_values, offset)
result = fe_field.setNodeParameters(
cache, -1, derivative, v + 1, new_values)
if result != RESULT_OK:
success = False
node = node_iter.next()
fm.endChange()
if not success:
print('zinc.transformCoordinates: failed to get/set some values')
return success
