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DPF Framework 2026 R1

invariant:principal invariants (fields container)

Last update: 31.07.2026

Version: 0.0.0

Description

Computes the element-wise Eigen values of all the tensor fields of a fields container.

Inputs

This table lists the input pins for this operator. Input pins define the data that the operator requires to perform its operation. Some inputs are required, while others are optional and provide additional configuration. Each parameter is detailed in the sections that follow the table.

Pin number Name Status Expected type(s)
0 fields_container Required fields_container

fields_container (Pin 0)

Outputs

This table lists the output pins for this operator. Output pins provide the results of the operator's computation and can be connected to inputs of other operators or retrieved for further processing. Each output is detailed in the sections that follow the table.

Pin number Name Expected type(s)
0 fields_eig_1 fields_container
1 fields_eig_2 fields_container
2 fields_eig_3 fields_container

fields_eig_1 (Pin 0)

first eigen value fields

fields_eig_2 (Pin 1)

second eigen value fields

fields_eig_3 (Pin 2)

third eigen value fields

Configurations

This operator supports configuration options that modify its behavior.

mutex

  • Expected type(s): bool
  • Default value: false

If this option is set to true, the shared memory is prevented from being simultaneously accessed by multiple threads.

num_threads

  • Expected type(s): int32
  • Default value: 0

Number of threads to use to run in parallel

run_in_parallel

  • Expected type(s): bool
  • Default value: true

Loops are allowed to run in parallel if the value of this config is set to true.

Scripting

This operator can be accessed through scripting interfaces using these identifiers.

Category: invariant

Plugin: core

Scripting name: principal_invariants_fc

Full name: invariant.principal_invariants_fc

Internal name: invariants_fc

License: None

Examples

These examples demonstrate how to use this operator in different programming environments. Each example shows how to instantiate the operator, connect the required inputs, and retrieve the output.

C++
#include "dpf_api.h"

ansys::dpf::Operator op("invariants_fc"); // operator instantiation
op.connect(0, my_fields_container);
ansys::dpf::FieldsContainer my_fields_eig_1 = op.getOutput<ansys::dpf::FieldsContainer>(0);
ansys::dpf::FieldsContainer my_fields_eig_2 = op.getOutput<ansys::dpf::FieldsContainer>(1);
ansys::dpf::FieldsContainer my_fields_eig_3 = op.getOutput<ansys::dpf::FieldsContainer>(2);
CPython
import ansys.dpf.core as dpf

op = dpf.operators.invariant.principal_invariants_fc() # operator instantiation
op.inputs.fields_container.connect(my_fields_container)
my_fields_eig_1 = op.outputs.fields_eig_1()
my_fields_eig_2 = op.outputs.fields_eig_2()
my_fields_eig_3 = op.outputs.fields_eig_3()
IPython
import mech_dpf
import Ans.DataProcessing as dpf

op = dpf.operators.invariant.principal_invariants_fc() # operator instantiation
op.inputs.fields_container.Connect(my_fields_container)
my_fields_eig_1 = op.outputs.fields_eig_1.GetData()
my_fields_eig_2 = op.outputs.fields_eig_2.GetData()
my_fields_eig_3 = op.outputs.fields_eig_3.GetData()

Changelog

  • Version 0.0.0: Initial release.

Connect with Ansys