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--- visual3d:documentation:pipeline:expressions:assigned_force_functions [2024/06/19 12:49] – sgranger
+++ visual3d:documentation:pipeline:expressions:assigned_force_functions [2024/09/11 17:22] (current) – Cleaned up formatting. wikisysop
@@ Line 1: / Line 1: @@
-the model based items [[visual3d:documentation:pipeline:model_based_data_commands:grf_data|grf_data]] and [[visual3d:documentation:pipeline:model_based_data_commands:cop_path|cop path]] are signals stored at the motion capture rate.
+====== Assigned Force Functions ======
-this is because these signals have the option to be resolved into a segment coordinate system and all segment coordinate systems (except the default lab) are at the motion capture rate.
-there are times, however, when it would be useful to get the force, cofp, and freemoment for the [[visual3d:documentation:kinematics_and_kinetics:external_forces:force_assignment|force assignment]] at the analog sample rate.
-===== forces =====
-**force**(segment)
+The model-based items [[Visual3D:Documentation:Pipeline:Model_Based_Data_Commands:GRF_DATA|GRF_DATA]] and [[Visual3D:Documentation:Pipeline:Model_Based_Data_Commands:COP_Path|COP Path]] are signals stored at the [[visual3d:documentation:c3d_signal_types:target_data_type|POINT data rate]]. This is because these signals have the option to be resolved into a Segment Coordinate System and all Segment Coordinate Systems (except the default LAB) are at the POINT rate. There are times, however, when it would be useful to get the Force, CofP, and FreeMoment signals for a given[[Visual3D:Documentation:Kinematics_and_Kinetics:External_Forces:Force_Assignment|force assignment]] at the [[visual3d:documentation:c3d_signal_types:analog_data_type|ANALOG sample rate]].
-select the force assigned to the left foot segment ([[visual3d:documentation:modeling:segments:segment_default_names|default segment name lft]]).
+==== Forces ====
-**evaluate_expression**
+Syntax: **FORCE**(segment)
-/expression=force("lft")
-/result_name=scott
-! /result_type=derived
-! /result_folder=processed
-**;**
-\\
+Example: Select the force assigned to the Left Foot segment (whose [[Visual3D:Documentation:Modeling:Segments:Segment_Default_Names|default segment name]] is LFT).
-===== center of pressure =====
+<code>
+Evaluate_Expression
+/EXPRESSION=FORCE("LFT")
+/RESULT_NAME=SCOTT
+! /RESULT_TYPE=DERIVED
+! /RESULT_FOLDER=PROCESSED
+;
+</code>
-**cofp**(segment)
+==== Center of Pressure ====
-select the center of pressure assigned to the left foot segment ([[visual3d:documentation:modeling:segments:segment_default_names|default segment name lft]]).
+Syntax: **COFP**(segment)
-**evaluate_expression**
+Example: Select the center of pressure assigned to the Left Foot segment (whose [[Visual3D:Documentation:Modeling:Segments:Segment_Default_Names|default segment name]] is LFT).
-/expression=cofp("lft")
-/result_name=scott
-! /result_type=derived
-! /result_folder=processed
-**;**
-===== free moment =====
-**freemoment**(segment)
+<code>
+Evaluate_Expression
+/EXPRESSION=COFP("LFT")
+/RESULT_NAME=SCOTT
+! /RESULT_TYPE=DERIVED
+! /RESULT_FOLDER=PROCESSED
+;
+</code>
-select the free moment assigned to the left foot segment ([[visual3d:documentation:modeling:segments:segment_default_names|default segment name lft]]).
+==== Free Moment ====
-**evaluate_expression**
+Syntax: **FREEMOMENT**(segment)
-/expression=freemoment("lft")
-/result_name=scott
-! /result_type=derived
-! /result_folder=processed
-**;**
-\\
+Example: Select the Free Moment assigned to the Left Foot segment (whose [[Visual3D:Documentation:Modeling:Segments:Segment_Default_Names|default segment name]] is LFT).
-===== error messages =====
+<code>
+Evaluate_Expression
+/EXPRESSION=FREEMOMENT("LFT")
+/RESULT_NAME=SCOTT
+! /RESULT_TYPE=DERIVED
+! /RESULT_FOLDER=PROCESSED
+;
+</code>
-**error messages**
+==== Error Messages ====
-there are several possible error messages related to the assigned forces function.
+There are several possible error messages related to the Assigned Forces expressions.
-**evaluate_expression**
+=== Segment Name must be Quoted ===
-/expression=force(junk)
+<code>
-/result_type=derived
+Evaluate_Expression
-/result_folder=processed
+/EXPRESSION=FORCE(JUNK)
-/result_name=test
+/RESULT_TYPE=DERIVED
-**;**
+/RESULT_FOLDER=PROCESSED
-**warning! no segment name was specified. did you forget the quotes?**
+/RESULT_NAME=TEST
-in order to ensure that a string containing the segment name is recognized quotes must be used.
+;
-**evaluate_expression**
-/expression=cofp("junk")
+WARNING! No Segment Name was specified. Did you forget the quotes?
-/result_type=derived
+</code>
-/result_folder=processed
-/result_name=test
+In order to ensure that a string containing the segment name is recognized quotes must be used.
-**;**
-**info! segment junk was not found**
+=== Segment Not in Link Model ===
-the segment was not part of the link model
+<code>
-**evaluate_expression**
+Evaluate_Expression
-/expression=cofp("right foot")
+/EXPRESSION=COFP("JUNK")
-/result_type=derived
+/RESULT_TYPE=DERIVED
-/result_folder=processed
+/RESULT_FOLDER=PROCESSED
-/result_name=test
+/RESULT_NAME=TEST
-**;**
+;
-**warning! evaluate_expression requires default segment names. for right foot use rft**
-visual3d has a set of [[visual3d:documentation:modeling:segments:segment_default_names|default segment names]] that must be used in expressions, so that the
+INFO! Segment Junk was not found
-expressions can be shared between users that have different config files.
+</code>
-**evaluate_expression**
-/expression=cofp("right fore foot")
+The segment must be a part of the Link Model in order to be findable.
-/result_type=derived
-/result_folder=processed
+=== Use Default Segment Names ===
-/result_name=test
+<code>
-**;**
+Evaluate_Expression
-**info! segment right fore foot is kinematic only, so there is no force assignment possible.**
+/EXPRESSION=COFP("Right Foot")
-only kinetic segments can be assigned a force.
+/RESULT_TYPE=DERIVED
+/RESULT_FOLDER=PROCESSED
+/RESULT_NAME=TEST
+;
+WARNING! Evaluate_Expression requires default segment names. For Right Foot use RFT
+</code>
+Visual3D has a set of [[Visual3D:Documentation:Modeling:Segments:Segment_Default_Names|default segment names]] that must be used in expressions, so that the expressions can be shared between users that have different config files.
+=== Can't Use Kinematic Only Segments ===
+<code>
+Evaluate_Expression
+/EXPRESSION=COFP("Right Fore Foot")
+/RESULT_TYPE=DERIVED
+/RESULT_FOLDER=PROCESSED
+/RESULT_NAME=TEST
+;
+INFO! Segment Right Fore Foot is Kinematic Only, so there is no Force Assignment possible.
+</code>
+Only kinetic segments can be assigned a force.