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--- visual3d:documentation:pipeline:metric_commands:metric_event_sequence_count [2025/09/24 13:48] – [Example: Time_Interval] wikisysop
+++ visual3d:documentation:pipeline:metric_commands:metric_event_sequence_count [2025/09/24 14:26] (current) – [Example: Time_Interval] wikisysop
@@ Line 62: / Line 62: @@
 |**When using a 5 second interval on a 20 second trial, the result will be four metrics (20/5).**\\ \\ (1) The first metric will contain the number of times the sequence occurs during the first 5 seconds of the trial\\ (2) The second metric will contain the number of times the sequence occurs during the 5 - 10 second interval of the trial\\ (3) The third metric will contain the number of times the sequence occurs during the 10 - 15 second interval of the trial\\ (4) The fourth metric will contain the number of times the sequence occurs during the 15 - 20 second interval of the trial\\ \\ **NOTE:** If the event sequence occurs between two intervals (LTO occurs at 4 sec and LHS occurs at 6 sec), this sequence will be included in Interval 1.  |  {{:EventsSequenceCount_Interval_Result.png}}|
+====Complex Example: Approximating Strides Using Angular Velocity Thresholds====
+As a subject moves through the gait cycle the angular velocities of their joints and limbs follow a known sequence with each stride. For this example we will identify this sequence for the right shank and use **Metric Event Sequence Count** to approximate the number of strides in a trial.
+As a subject walks or runs their knees go through an alternating cycle of flexion and extension. This can be seen through many measurements, including the X component angular velocity of their shank. Here we use the **Event Threshold** command to identify each time that the angular velocity of the subject's right shank crosses 0 and goes from negative to positive or vice versa.
+<code>
+Event_Threshold
+/RESULT_EVENT_NAME=RSK_Positive
+/SIGNAL_TYPES=KINETIC_KINEMATIC
+/SIGNAL_FOLDER=RSK
+/SIGNAL_NAMES=AngVel
+/SIGNAL_COMPONENTS=X
+! /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
+/THRESHOLD=0
+/ON_ASCENT=TRUE
+/ON_DESCENT=FALSE
+! /FRAME_WINDOW=8
+! /ENSURE_FRAMES_BEFORE=FALSE
+! /ENSURE_FRAMES_AFTER=FALSE
+;
+</code>
+<code>
+Event_Threshold
+/RESULT_EVENT_NAME=RSK_Negative
+/SIGNAL_TYPES=KINETIC_KINEMATIC
+/SIGNAL_FOLDER=RSK
+/SIGNAL_NAMES=AngVel
+/SIGNAL_COMPONENTS=X
+! /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
+/THRESHOLD=0
+/ON_ASCENT=FALSE
+/ON_DESCENT=TRUE
+! /FRAME_WINDOW=8
+! /ENSURE_FRAMES_BEFORE=FALSE
+! /ENSURE_FRAMES_AFTER=FALSE
+;
+</code>
+Now, using these events we can use **Metric Event Sequence Count** to count the number of instances in which the right knee goes from flexing into extending and back again, with each of these representing one stride.
+<code>
+Metric_Event_Sequence_Count
+! /RESULT_METRIC_FOLDER=PROCESSED
+/RESULT_METRIC_NAME=RSK_flexion_extension
+! /TIME_INTERVAL=
+/EVENT_SEQUENCE=RSK_Positive+RSK_Negative
+/EXCLUDE_EVENTS=
+! /GENERATE_COUNT_TOTAL_IN_GLOBAL=TRUE
+;
+</code>
+A new folder should now be present in the **METRIC** folder containing a count of the event sequence. This number corresponds to the number of strides taken in a trial, which can be confirmed through further analysis or by watching the trial simulation.
+{{:visual3d:documentation:pipeline:metric_commands:rsk_count.png?500|}}