math:fft filtering and cubic fitting
Last update: 31.07.2026Version: 0.0.0
Description
Computes the fitting curve using FFT filtering and cubic fitting in space (node i: x=time, y=data), with the possibility to compute the first and the second derivatives of the curve.
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 | time_scoping | vector<int32>, scoping |
|
| 1 | mesh_scoping | umap<int32,int32>, scoping, scopings_container |
|
| 2 | entity_to_fit | Required | fields_container |
| 3 | component_number | Required | int32 |
| 4 | first_derivative | Required | bool |
| 5 | second_derivative | Required | bool |
| 6 | fit_data | Required | bool |
| 7 | cutoff_fr | double, int32 |
time_scoping (Pin 0)
- Required: No
- Expected type(s):
vector<int32>,scoping
A time scoping to rescope / split the fields container given as input.
mesh_scoping (Pin 1)
- Required: No
- Expected type(s):
umap<int32,int32>,scoping,scopings_container
A space (mesh entities) scoping (or scopings container) to rescope / split the fields container given as input.
entity_to_fit (Pin 2)
- Required: Yes
- Expected type(s):
fields_container
Data changing in time to be fitted.
component_number (Pin 3)
- Required: Yes
- Expected type(s):
int32
Component number as an integer, for example '0' for X-displacement, '1' for Y-displacement, and so on.
first_derivative (Pin 4)
- Required: Yes
- Expected type(s):
bool
Calculate the first derivative (bool). The default is false.
second_derivative (Pin 5)
- Required: Yes
- Expected type(s):
bool
Calculate the second derivative (bool). The default is false.
fit_data (Pin 6)
- Required: Yes
- Expected type(s):
bool
Calculate the fitted values (bool). The default is false
cutoff_fr (Pin 7)
Cutoff frequency.
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 | fitted_entity_y | fields_container |
| 1 | first_der_dy | fields_container |
| 2 | second_der_d2y | fields_container |
fitted_entity_y (Pin 0)
- Expected type(s):
fields_container
The fitted entity is fitted using FFT along the space scoping (node i: x=time, y=data). Fitted Y is expected to be close to the input data.
first_der_dy (Pin 1)
- Expected type(s):
fields_container
The first derivative (dY) from the fitted Y.
second_der_d2y (Pin 2)
- Expected type(s):
fields_container
The second derivative (d2Y) from the fitted Y.
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: math
Plugin: core
Scripting name: fft_approx
Full name: math.fft_approx
Internal name: fft_approx
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("fft_approx"); // operator instantiation
op.connect(0, my_time_scoping);
op.connect(1, my_mesh_scoping);
op.connect(2, my_entity_to_fit);
op.connect(3, my_component_number);
op.connect(4, my_first_derivative);
op.connect(5, my_second_derivative);
op.connect(6, my_fit_data);
op.connect(7, my_cutoff_fr);
ansys::dpf::FieldsContainer my_fitted_entity_y = op.getOutput<ansys::dpf::FieldsContainer>(0);
ansys::dpf::FieldsContainer my_first_der_dy = op.getOutput<ansys::dpf::FieldsContainer>(1);
ansys::dpf::FieldsContainer my_second_der_d2y = op.getOutput<ansys::dpf::FieldsContainer>(2);
CPython
import ansys.dpf.core as dpf
op = dpf.operators.math.fft_approx() # operator instantiation
op.inputs.time_scoping.connect(my_time_scoping)
op.inputs.mesh_scoping.connect(my_mesh_scoping)
op.inputs.entity_to_fit.connect(my_entity_to_fit)
op.inputs.component_number.connect(my_component_number)
op.inputs.first_derivative.connect(my_first_derivative)
op.inputs.second_derivative.connect(my_second_derivative)
op.inputs.fit_data.connect(my_fit_data)
op.inputs.cutoff_fr.connect(my_cutoff_fr)
my_fitted_entity_y = op.outputs.fitted_entity_y()
my_first_der_dy = op.outputs.first_der_dy()
my_second_der_d2y = op.outputs.second_der_d2y()
IPython
import mech_dpf
import Ans.DataProcessing as dpf
op = dpf.operators.math.fft_approx() # operator instantiation
op.inputs.time_scoping.Connect(my_time_scoping)
op.inputs.mesh_scoping.Connect(my_mesh_scoping)
op.inputs.entity_to_fit.Connect(my_entity_to_fit)
op.inputs.component_number.Connect(my_component_number)
op.inputs.first_derivative.Connect(my_first_derivative)
op.inputs.second_derivative.Connect(my_second_derivative)
op.inputs.fit_data.Connect(my_fit_data)
op.inputs.cutoff_fr.Connect(my_cutoff_fr)
my_fitted_entity_y = op.outputs.fitted_entity_y.GetData()
my_first_der_dy = op.outputs.first_der_dy.GetData()
my_second_der_d2y = op.outputs.second_der_d2y.GetData()
Changelog
- Version 0.0.0: Initial release.