Table of Contents
Event Maximum
Overview
The Event_Maximum command is used to detect the maximum value of a specified signal within a defined event sequence or range and create an event at that location. This command can evaluate different components of a signal (X, Y, Z, Residual) and can apply offsets to shift the detected event if needed.
- Useful for identifying peak forces, peak joint angles, or maximum accelerations during specific phases of a motion, such as between initial contact and toe-off during gait.
- If the global maxima are needed, see the Event_Global_Maximum command
- To review the difference between local and global maximum values please see here
Pipeline Command
The command below is as seen in the Visual3D application:
Event_Maximum /RESULT_EVENT_NAME= ! /SIGNAL_TYPES= ! /SIGNAL_FOLDER=ORIGINAL ! /SIGNAL_NAMES= ! /SIGNAL_COMPONENTS= ! /FRAME_OFFSET=0 ! /TIME_OFFSET= ! /EVENT_SEQUENCE= ! /EXCLUDE_EVENTS= ! /EVENT_SEQUENCE_INSTANCE=0 ! /EVENT_SUBSEQUENCE= ! /SUBSEQUENCE_EXCLUDE_EVENTS= ! /EVENT_SUBSEQUENCE_INSTANCE=0 ! /EVENT_INSTANCE=0 ! /FRAME_WINDOW=8 ! /THRESHOLD= ;
Command Parameters
The following table shows the command parameters and descriptions:
| Parameter | Description |
| /RESULT_EVENT_NAME= | The name assigned to the detected peak event. |
| !/SIGNAL_TYPES= | Indicates type of signal analyzed. |
| !/SIGNAL_FOLDER=ORIGINAL | Specifies the folder containing the target signal (typically ORIGINAL) |
| !/SIGNAL_NAMES= | The name of the signal to analyze. |
| !/SIGNAL_COMPONENTS | Which components to evaluate (X, Y, Z, Residual) |
| !/FRAME_OFFSET= | Optional offset in frames to shift the detected event. |
| !/TIME_OFFSET= | Optional offset in seconds to shift the detected event. |
| !/EVENT_SEQUENCE= | Defines the sequence of events used. |
| !/EXCLUDE_EVENTS= | Events to exclude within the sequence. |
| !/EVENT_SEQUENCE_INSTANCE=0 | Specifies which instance of the sequence to evaluate (0 to consider ALL) |
| !/EVENT_SUBSEQUENCE= | Defines a smaller sequence within the main even sequence. |
| !/SUBSEQUENCE_EXCLUDE_EVENTS | Events to exclude from the subsequence. |
| !/EVENT_SUBSEQUENCE_INSTANCE=0 | Specifies which instance of the subsequence to evaluate. |
| !/EVENT_INSTANCE= | Specifies which instance of the event to label (0 for all, positive for first occurrences, negative for last occurrences). |
| !/FRAME_WINDOW= | Number of frames around the maximum that must satisfy the threshold. |
| !/THRESHOLD= | Defines the minimum value the signal must reach to qualify as a peak. |
Dialog
The command can be edited in a text editor or in the dialog. To edit in the dialog, click on the Edit button in the pipeline workshop or double-click on the pipeline command. The dialog is shown below:
Examples
The following examples will go through the use of the Event_Maximum command in the Visual3D application.
Example 1: Simple Use Case
The first example will cover the command using the dialog as well as the command text. To create the RKFlex_MaxLocal event using the Event_Maximum dialog box:
1. Add the Event_Maximum command to the pipeline. Then, enter information into dialog box:
Event_Name: RKFlex_MaxLocal
Select Frame Offset: 0
Signal Components: X
Event Sequence:RHS → RHS (use arrows to move from defined events list into sequence.)
Event Sequence Instance:0
2. Close the dialog, on the Signals and Events tab, select the desired signal from the data tree, in this case Right_Knee_Angle. Navigate into the LINK_MODEL_BASED items folder, and select the checkbox beside the signal.
3. Open the pipeline workshop again, and then click on Import Selected Signals.
RKFlex_Max will be created at the minimum value during the gait cycle within the specified frame window.
Notes
Version 5
In version 5 the command has been extended to include the Event_Sequence and Exclude_Events parameters.
 | Event_Maximum /RESULT_EVENT_NAME=EVENT_MAX /SIGNAL_TYPES=TARGET /SIGNAL_FOLDER=ORIGINAL /SIGNAL_NAMES=LFT2 /SIGNAL_COMPONENTS=Z /FRAME_OFFSET=0 !/TIME_OFFSET= !/EVENT_SEQUENCE= !/EXCLUDE_EVENTS= !/EVENT_SEQUENCE_INSTANCE=0 !/EVENT_SUBSEQUENCE= !/SUBSEQUENCE_EXCLUDE_EVENTS= !/EVENT_INSTANCE=0 !/FRAME_WINDOW-8 /THRESHOLD=0.14 ; |
- Other options within the command such as Exclude Event, and Select Subsequence are explained in detail on the Event_Global_Maximum page.
- If /Threshold is empty, all local maximum are identified.
- If /Threshold has a value or expression, only local maximum that are greater than the threshold are identified.
Version 4
Event_Maximum /Signal_Types=The type of signal to be evaluated /Signal_Names=The names of the signals to be evaluated /Signal_Folder=The name of the signal folder /Event_Name=The name to be given to the threshold event /Select_X=(True or False)Use this component of the signal /Select_Y=(True or False)Use this component of the signal /Select_Z=(True or False)Use this component of the signal /Frame_Window=The range of frames of data that must be below the maximum /Start_At_Event=The search begins from the start event /End_At_Event=The search ends at the end event /Event_Instance= ;
Dialog that pops up when pipeline selection is edited by double clicking with the left mouse button.
