DPF - How to retrieve quantities only on corner nodes of a given named selection?

Pierre Thieffry

User has created a name selection on a face, yet wants to extract stress values only at corner nodes. How can he do this?

Pierre Thieffry

Not sure this is the cleanest way, but the below code will work. The idea is to collect a list of all corner nodes from the mesh, then intersect a named selection's ids with this list and scope results to this restricted list of nodes

import mech_dpf
import Ans.DataProcessing as dpf
import Ans.DataProcessing.operators as ops

mech_dpf.setExtAPI(ExtAPI)
my_data_source = mech_dpf.GetDataSources()

ns = ops.scoping.on_named_selection()
ns.inputs.data_sources.Connect(my_data_source)
ns.inputs.requested_location.Connect("Nodal")
ns.inputs.named_selection_name.Connect("FACE")

model=dpf.Model(my_data_source)
model.ReleaseStreams()

rst_mesh=model.Mesh
corner_nodes=[]

# Parse all nodes to find corner node ids
all_elems=rst_mesh.Elements
for el in all_elems:
    corner_nodes.extend(el.CornerNodeIds)
# Remove duplicates
corner_nodes=list(dict.fromkeys(corner_nodes))

# Create node scoping only on corner nodes
# intersection of full list of corner_nodes and scoping from above named selection
corner_scoping=dpf.Scoping()
corner_scoping.Ids=list(set(corner_nodes) & set(ns.outputs.mesh_scoping.GetData().Ids))

# Retrieve whichever result, scoped on corner nodes of interest
stress_op = ops.result.stress_X()
stress_op.inputs.data_sources.Connect(my_data_source)
stress_op.inputs.mesh_scoping.Connect(corner_scoping)

my_stress = stress_op.outputs.fields_container.GetData()[0]

for id in my_stress.ScopingIds:
    print(id,my_stress.GetEntityDataById(id)[0])