Narrow down data

MAPDL LS-DYNA FLUENT CFX

This tutorial explains how to scope your results over time and mesh domains.

Understanding the scope

To begin the workflow setup, you need to establish the scoping, that is a spatial and/or temporal subset of the simulation data.

The data in DPF is represented by a Field. Thus, narrowing down your results means scoping your Field. To do so in DPF, you use the Scoping object. You can retrieve all the time steps available for a result, but you can also filter them.

Note

Scoping is important because when DPF-Core returns the Field object, what Python actually has is a client-side representation of the Field, not the entirety of the Field itself. The most efficient way of interacting with result data is to minimize the exchange of data between Python and DPF, either by using operators or by accessing exclusively the data that is needed. For more information on the DPF data storage structures see DPF data structures.

In conclusion, the essence of a scoping is to specify a set of time or mesh entities by defining a range of IDs:

Import the PyDPF-Core modules

# Import the ``ansys.dpf.core`` module
from ansys.dpf import core as dpf

Create a Scoping from scratch — instantiate the Scoping class

Create a time Scoping and a mesh Scoping by instantiating the Scoping object. Use the ids and location arguments to give the entities ids and location of interest.

Time scoping — use a 'time_freq' location and target time sets by their ids.

time_list_1 = [14, 15, 16, 17]
time_scoping_1 = dpf.Scoping(ids=time_list_1, location=dpf.locations.time_freq)

Mesh scoping — use a nodal location and target nodes by their ids.

nodes_ids_1 = [103, 204, 334, 1802]
mesh_scoping_1 = dpf.Scoping(ids=nodes_ids_1, location=dpf.locations.nodal)

Create a Scoping using the scoping factory modules

Use the time_freq_scoping_factory module for a temporal Scoping and the mesh_scoping_factory module for a spatial Scoping.

Time scoping — use the scoping_by_sets() function to create a Scoping over multiple time sets.

time_list_2 = [14, 15, 16, 17]
time_scoping_2 = dpf.time_freq_scoping_factory.scoping_by_sets(cumulative_sets=time_list_2)

Mesh scoping — use the nodal_scoping() function to create a nodal mesh Scoping.

nodes_ids_2 = [103, 204, 334, 1802]
mesh_scoping_2 = dpf.mesh_scoping_factory.nodal_scoping(node_ids=nodes_ids_2)

Define the objects needed to extract Scopings

Import a result file and create a Model. For this tutorial, use one available in the examples module. For more information about how to import your own result file in DPF, see the Import a result file in DPF tutorial.

# Import the operators and examples module
from ansys.dpf.core import examples, operators as ops

# Define the result file path
result_file_path_1 = examples.download_transient_result()

# Create the DataSources object
ds_1 = dpf.DataSources(result_path=result_file_path_1)

# Create the model
model_1 = dpf.Model(data_sources=ds_1)

Extract the mesh (MeshedRegion), a FieldsContainer with displacement results, and a single Field.

# Get the MeshedRegion
meshed_region_1 = model_1.metadata.meshed_region

# Get a FieldsContainer with the displacement results
disp_fc = model_1.results.displacement.on_all_time_freqs.eval()

# Get a Field from the FieldsContainer
disp_field = disp_fc[0]

Extract the time Scoping

Extracting the time Scoping means extracting the scoping of the time frequencies from the TimeFreqSupport of a DPF object.

From the Model

Access the TimeFreqSupport via the model metadata, then get the time frequencies Field and extract its scoping.

tfs_1 = model_1.metadata.time_freq_support
t_freqs_1 = tfs_1.time_frequencies
time_scop_1 = t_freqs_1.scoping
print(time_scop_1)

DPF  Scoping:
  with TimeFreq_steps location and 1 entity

From the FieldsContainer

tfs_2 = disp_fc.time_freq_support
t_freqs_2 = tfs_2.time_frequencies
time_scop_2 = t_freqs_2.scoping
print(time_scop_2)

DPF  Scoping:
  with TimeFreq_steps location and 1 entity

From the Field

tfs_3 = disp_field.time_freq_support
t_freqs_3 = tfs_1.time_frequencies
time_scop_3 = t_freqs_3.scoping
print(time_scop_3)

DPF  Scoping:
  with TimeFreq_steps location and 1 entity

Extract the mesh Scoping

From the MeshedRegion

Use the from_mesh operator to get the Scoping for the entire mesh. It returns a nodal scoping by default; use the requested_location argument for an elemental scoping.

mesh_scoping_3 = ops.scoping.from_mesh(mesh=meshed_region_1).eval()
print("Scoping from mesh:", "\n", mesh_scoping_3, "\n")

Scoping from mesh:
 DPF  Scoping:
  with Nodal location and 3820 entities

Use the MeshedRegion.elements method and then Elements.scoping to get an elemental Scoping.

mesh_scoping_4 = meshed_region_1.elements.scoping
print("Scoping from mesh elements:", "\n", mesh_scoping_4, "\n")

Scoping from mesh elements:
 DPF  Scoping:
  with Elemental location and 789 entities

Use the MeshedRegion.nodes method and then Nodes.scoping to get a nodal Scoping.

mesh_scoping_5 = meshed_region_1.nodes.scoping
print("Scoping from mesh nodes:", "\n", mesh_scoping_5, "\n")

Scoping from mesh nodes:
 DPF  Scoping:
  with Nodal location and 3820 entities

From the FieldsContainer

Use the extract_scoping operator. This operator gets the mesh Scoping for each Field in the FieldsContainer, returning a ScopingsContainer.

extract_scop_fc_op = ops.utility.extract_scoping(field_or_fields_container=disp_fc)
mesh_scoping_6 = extract_scop_fc_op.outputs.mesh_scoping_as_scopings_container()
print("Scoping from FieldsContainer:", "\n", mesh_scoping_6, "\n")

Scoping from FieldsContainer:
 DPF  Scopings Container
  with 35 scoping(s)
  defined on labels: time

  with:
  - scoping 0 {time:  1, } located on Nodal 3820 entities.
  - scoping 1 {time:  2, } located on Nodal 3820 entities.
  - scoping 2 {time:  3, } located on Nodal 3820 entities.
  - scoping 3 {time:  4, } located on Nodal 3820 entities.
  - scoping 4 {time:  5, } located on Nodal 3820 entities.
  - scoping 5 {time:  6, } located on Nodal 3820 entities.
  - scoping 6 {time:  7, } located on Nodal 3820 entities.
  - scoping 7 {time:  8, } located on Nodal 3820 entities.
  - scoping 8 {time:  9, } located on Nodal 3820 entities.
  - scoping 9 {time:  10, } located on Nodal 3820 entities.
  - scoping 10 {time:  11, } located on Nodal 3820 entities.
  - scoping 11 {time:  12, } located on Nodal 3820 entities.
  - scoping 12 {time:  13, } located on Nodal 3820 entities.
  - scoping 13 {time:  14, } located on Nodal 3820 entities.
  - scoping 14 {time:  15, } located on Nodal 3820 entities.
  - scoping 15 {time:  16, } located on Nodal 3820 entities.
  - scoping 16 {time:  17, } located on Nodal 3820 entities.
  - scoping 17 {time:  18, } located on Nodal 3820 entities.
  - scoping 18 {time:  19, } located on Nodal 3820 entities.
  - scoping 19 {time:  20, } located on Nodal 3820 entities.
  - scoping 20 {time:  21, } located on Nodal 3820 entities.
  - scoping 21 {time:  22, } located on Nodal 3820 entities.
  - scoping 22 {time:  23, } located on Nodal 3820 entities.
  - scoping 23 {time:  24, } located on Nodal 3820 entities.
  - scoping 24 {time:  25, } located on Nodal 3820 entities.
  - scoping 25 {time:  26, } located on Nodal 3820 entities.
  - scoping 26 {time:  27, } located on Nodal 3820 entities.
  - scoping 27 {time:  28, } located on Nodal 3820 entities.
  - scoping 28 {time:  29, } located on Nodal 3820 entities.
  - scoping 29 {time:  30, } located on Nodal 3820 entities.
  - scoping 30 {time:  31, } located on Nodal 3820 entities.
  - scoping 31 {time:  32, } located on Nodal 3820 entities.
  - scoping 32 {time:  33, } located on Nodal 3820 entities.
  - scoping 33 {time:  34, } located on Nodal 3820 entities.
  - scoping 34 {time:  35, } located on Nodal 3820 entities.

From the Field

Use the extract_scoping operator or the Field.scoping method.

mesh_scoping_7 = ops.utility.extract_scoping(field_or_fields_container=disp_field).eval()
print("Scoping from Field (operator):", "\n", mesh_scoping_7, "\n")

mesh_scoping_8 = disp_field.scoping
print("Scoping from Field (method):", "\n", mesh_scoping_8, "\n")

Scoping from Field (operator):
 DPF  Scoping:
  with Nodal location and 3820 entities


Scoping from Field (method):
 DPF  Scoping:
  with Nodal location and 3820 entities

Extract and scope the results

Apply a Scoping when extracting a result using the Model.results method or the result operator inputs. Pass the Scoping objects to the time_scoping and mesh_scoping arguments.

# Extract and scope using Model.results
disp_model = model_1.results.displacement(
    time_scoping=time_scoping_1, mesh_scoping=mesh_scoping_1
).eval()

# Extract and scope using the result.displacement operator
disp_op = ops.result.displacement(
    data_sources=ds_1, time_scoping=time_scoping_1, mesh_scoping=mesh_scoping_1
).eval()

print("Displacement from Model.results:", "\n", disp_model, "\n")
print("Displacement from result.displacement operator:", "\n", disp_op, "\n")

Displacement from Model.results:
 DPF displacement(s)Fields Container
  with 4 field(s)
  defined on labels: time

  with:
  - field 0 {time:  14} with Nodal location, 3 components and 4 entities.
  - field 1 {time:  15} with Nodal location, 3 components and 4 entities.
  - field 2 {time:  16} with Nodal location, 3 components and 4 entities.
  - field 3 {time:  17} with Nodal location, 3 components and 4 entities.


Displacement from result.displacement operator:
 DPF displacement(s)Fields Container
  with 4 field(s)
  defined on labels: time

  with:
  - field 0 {time:  14} with Nodal location, 3 components and 4 entities.
  - field 1 {time:  15} with Nodal location, 3 components and 4 entities.
  - field 2 {time:  16} with Nodal location, 3 components and 4 entities.
  - field 3 {time:  17} with Nodal location, 3 components and 4 entities.

Extract and rescope the results

Change the mesh Scoping after result extraction or manipulation using the rescope operator. It takes a Field or FieldsContainer and rescopes it to the given Scoping.

# Extract the results for the entire mesh
disp_all_mesh = model_1.results.displacement.eval()

# Rescope the displacement results to a specific set of nodes
disp_rescope = ops.scoping.rescope(fields=disp_all_mesh, mesh_scoping=mesh_scoping_1).eval()

print("Displacement results for the entire mesh:", "\n", disp_all_mesh, "\n")
print("Displacement results rescoped:", "\n", disp_rescope, "\n")

Displacement results for the entire mesh:
 DPF displacement(s)Fields Container
  with 1 field(s)
  defined on labels: time

  with:
  - field 0 {time:  35} with Nodal location, 3 components and 3820 entities.


Displacement results rescoped:
 DPF displacement(s)Fields Container
  with 1 field(s)
  defined on labels: time

  with:
  - field 0 {time:  35} with Nodal location, 3 components and 4 entities.