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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

Interpolate

Replace

Set_Data_To_New_Values

Set Data To New Values

Rectify

First_Derivative

First Derivative

Second_Derivative

Second Derivative

Transform_Data_Coordinate_System

Examples

Example_-_Intersection_of_two_lines

Compute the intersection of two lines

Example_-_Intersection_of_a_line_and_a_plane

Compute the intersection of a line with a plane

Example_-_Computing_the_head_fixation_point

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. This examples makes use of the example for computing the Intersection of 2 Lines found above.

HAS-Motion Software Documentation

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