visual3d:documentation:pipeline:signal_commands:signal_commands_overview
Table of Contents
Signal Commands Overview
Signal commands are used to manipulate signals within the Visual3D pipeline.
Signal Math
These commands perform mathematical operations using signals.
| Command | Description |
|---|---|
| Evaluate_Expression | Can be used to flexibly define custom mathematical functions. |
| Add_Constant_To_Signals | Adds a constant to the specified components of a signal(s). |
| Add_Random_Noise_To_Signals | Adds random noise to the specified signal(s). |
| Add_Signals | Add the specified signals. Signals must be at the same sampling rate. If your signals are a different rate, you can use the Evaluate_Expression command, which determines an appropriate rate automatically. |
| Divide_Signals | This command will divide signals with the first signal being the numerator. |
| Divide_Signal_By_Constant | This command will divide a specified components of a signal(s) by a constant. |
| First_Derivative | Compute the first derivative at each point of a signal. This command is useful for calculating the velocity of targets, landmarks, etc. |
| Second_Derivative | Compute the second derivative at each point of a signal. This command is useful for calculating the acceleration of targets, landmarks, etc. |
| Multiply_Signals | Multiply the components of the specified signals. |
| Multiply_Signals_By_Constant | Multiply signals by a constant value. |
| Indefinite_Integral | Compute an indefinite integral from the start event to the stop event. |
| Signal_Magnitude | Calculate the magnitude of a signal according to: Magnitude=Sqrt( x^2+y^2+z^2 ) |
| Subtract_Constant_From_Signals | Subtracts a constant from the specified components of a signal(s). |
| Subtract_Signals | Subtract the components of the specified signals. |
| Square_Root | Compute the square root of a signal or metric. This command can be used to compute the vector magnitude of a signal. |
| Compute_Planar_Angle | This command computes a planar angle between three or four points. |
| Compute_Volume_Of_Chest_Wall | |
| Compute_Volume_Of_A_Convex_Hull |
Signal/Data Management
These commands manage signals within the Visual3D workspace.
| Command | Description |
|---|---|
| Create_Target | |
| Global_Normalized_Signal_Mean | |
| Find_Representative_Signal | |
| Merge_Data | This command merges data from more than one data name into a single one either by appending one signal to the end of another signal or by treating each original signal as a component of the new signal. |
| Copy_Folder | Makes a copy of an existing folder. If the new folder already exists, select whether these signals should be overwritten (replaced). |
| Rename_Folder | This command renames the specified folder. |
| Delete_Folder | Deletes the specified folder. Note that ORIGINAL folders can not be deleted. |
| Remove_Signals | |
| Rename_Signals | |
| Remove_Unlabeled_Points | Vicon Nexus exports unlabeled trajectories identified with an asterisk (*) at the beginning of the filename. |
| Remove_Polygon_Signals | Remove processed signals generated by Polygon and stored as POINT data in the C3D file. |
Signal Filter
These commands apply filters to signals within the Visual3D workspace.
| Command | Description |
|---|---|
| Average_Filter | |
| Butterworth_Filter | Matlab's FDA tool can be used to design a notch filter using this command. |
| FFT_Filter | |
| GCVSPL | |
| Lowpass Filter | |
| Highpass Filter | |
| Onepass_Filter | |
| Median_Filter | |
| Moving_RMS | |
| Shift_Frames | |
| Teager_Kaiser_Energy | The Teager-Kaiser Energy Operator. |
Signal Process
These commands process signals within the Visual3D workspace. For signal filters see the Signal Filter section of this page.
Examples
This wiki contains examples of how these signal commands can be used to accomplish common analytical tasks.
- Compute the intersection of two lines (under construction)
- Compute the intersection of a line with a plane (under construction)
The head fixation point is the intersection between the anterior direction of the head at one frame of time and an another frame of time. The head fixation point can be computed using the above example for the intersection of two lines.
visual3d/documentation/pipeline/signal_commands/signal_commands_overview.txt · Last modified: 2025/07/11 16:12 by wikisysop