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--- visual3d:documentation:pipeline:expressions:expression_items [2024/07/17 15:22] – sgranger
+++ visual3d:documentation:pipeline:expressions:expression_items [2024/10/09 18:38] (current) – Left page as a "redirect", all backlinks have been removed. wikisysop
@@ Line 1: / Line 1: @@
-====== Expression Items ======
+This page has been move to [[visual3d:documentation:pipeline:expressions:expression_syntax|Expression Syntax]].
-==== Contents ====
-  * [[#Data_Tree|1 Data_Tree]]
-    * [[#Examples_for_Specifying_a_Data_Tree_Signal|1.1 Examples for Specifying a Data Tree Signal]]
-  * [[#Model_Builder|2 Model_Builder]]
-    * [[#Creating_a_Landmark_at_the_center_of_a_ball|2.1 Creating a Landmark at the center of a ball]]
-  * [[#Pipeline_Parameters|3 Pipeline_Parameters]]
-    * [[#Using_a_pipeline_parameter_as_part_of_a_signal_definition|3.1 Using a pipeline parameter as part of a signal definition]]
-  * [[#Tags|4 Tags]]
-  * [[#C3D_Parameters|5 C3D_Parameters]]
-  * [[#Model_Metrics|6 Model_Metrics]]
-    * [[#Specifying_an_item_from_a_model|6.1 Specifying an item from a model]]
-==== Data_Tree ====
-Signals should be placed into the expression in the form:
-SIGNAL_TYPE::SIGNAL_FOLDER::SIGNAL_NAME
-To define a specific element of a signal (e.g. the X Component)
-SIGNAL_TYPE::SIGNAL_FOLDER::SIGNAL_NAME::X
-To define a specific frame of a data of signal (e.g. Frame 2)
-SIGNAL_TYPE::SIGNAL_FOLDER::SIGNAL_NAME[2]
-Data stored in the GLOBAL Workspace should be expressed as follows:
-GLOBAL::SIGNAL_TYPE::SIGNAL_FOLDER::SIGNAL_NAME
-NOTE: Global signals can be accessed regardless of the ACTIVE FILES.
-=== Examples for Specifying a Data Tree Signal ===
-TARGET::ORIGINAL::RFT1 = Signal RFT1 in the TARGET type and ORIGINAL folder
-ANALOG::PROCESSED::FX1 = Signal FX1 in the ANALOG type and PROCESSED folder
-PARAMETER::ANALOG::RATE= Parameter RATE in the ANALOG group of the C3D PARAMETERS
-==== Model_Builder ====
-Model metrics have a simpler syntax. The Signal Type and Signal Folder need not be specified because there is only one version of a signal.
-== Creating a Landmark at the center of a ball ==
-Given 6 markers placed on the surface of a round ball
-BALL1, BALL2, BALL3, BALL4, BALL5, BALL6
-Create a model metric at the center of a best fit sphere to the ball.
-Metric Name= BALL
-Metric Expression = Best_Fit_Sphere(List(BALL1, BALL2, BALL3, BALL4, BALL5, BALL6))
-The resulting metric will have 3 values separated by a comma (e.g. the 3 components of the center)
-As an example a center value of (0.5, 0.6, 0.7) would appear as
-.5,0.6,0.7
-Create a landmark using this metric data
-{{:BallCenterLandmark.jpg}}
-Note the syntax for the offsets
-BALL[1,1]
-The syntax may seem a little strange, but [1,1] refers to the first element of the first frame
-==== Pipeline_Parameters ====
-The syntax for using a pipeline parameter as part of an expression is a bit unusual and takes an understanding of how Visual3D parses parameters and pre-processes commands.
-The ampersand & is used in pipeline commands to concatenate strings together, and thus is a separator for the parser to find the pieces that need to be parsed separately.
-For example, to use a pipeline parameter LP_FREQ:
-/EXPRESSION=2*pi()*&::LP_FREQ
-The ampersand tells the parser to take the 2*pi()* and the ::LP_FREQ separately through the pre-parser. The first part is just taken as is since it doesn't have a prefix of ::. The value after the & does have a :: prefix, so it is substituted with the pipeline parameter.
-If you have more complex expressions, you might need to surround each pipeline parameter with an ampersand
-&::LP_FREQ&*&::MULTIPLIER&-&::CONSTANT which may evaluate to something like: 60*1.4-90.0 once all the pipeline parameters are substituted.
-The general rule is to surround the pipeline parameter with ampersands.
-=== Using a pipeline parameter as part of a signal definition ===
-The syntax is a little funky when it comes to using pipeline parameters in the middle of a signal definition because of the order in which equations are parsed.
-The following subtracts two signals.
-**Evaluate_Expression**
-/EXPRESSION=ANALOG::FILTERED&:&:&::INDEX&:&:&X&-METRIC::PROCESSED&:&:&::INDEX&_zero
-/RESULT_NAME=::INDEX
-/RESULT_TYPE=ANALOG
-/RESULT_FOLDER=OFFSET
-**;**
-==== Tags ====
-TAGS can be expressed as follows:
-TAG::TAG_NAME
-==== C3D_Parameters ====
-C3D Parameters can be expressed as follows:
-PARAMETER::GROUP::PARAMETER_NAME
-==== Model_Metrics ====
-=== Specifying an item from a model ===
-The following Model data is available.
-MODEL::METRIC::NAME
-MODEL::SEGMENT::segname::LENGTH
-MODEL::SEGMENT::segname::DEPTH
-MODEL::SEGMENT::segname::CENTER_OF_MASS
-MODEL::SEGMENT::segname::IXX
-MODEL::SEGMENT::segname::IYY
-MODEL::SEGMENT::segname::IZZ
-MODEL::SEGMENT::segname::MASS
-MODEL::SEGMENT::segname::PROXIMAL_RADIUS
-MODEL::SEGMENT::segname::DISTAL_RADIUS
-MODEL::SEGMENT::segname::ORIGIN
-To refer to a marker
-MODEL::TARGET::MARKER_NAME
-If you want to refer to a specific component of a signal
-MODEL::TARGET::MARKER_NAME::X
-To refer to a landmark
-MODEL::LANDMARK::LANDMARK_NAME
-To refer to a force. **NOTE** This will be available in version 5.0
-MODEL::FORCE::FP1
-The following command will create a global signal containing the average value of the signal FORCE::FP1 over the range of frames specified for the model (e.g. if a range is not specified, all frames will be used).
-The command is executed once for each active file, so the resulting signal will continually be overwritten and the last file processed will correspond to the resulting signal.
-**Evaluate_Expression**
-/EXPRESSION=MODEL::FORCE::FP1
-/RESULT_NAME=GLOBAL::SCOTT
-/RESULT_TYPE=DERIVED
-! /RESULT_FOLDER=PROCESSED
-**;**
-If you edit commands in the text editor, which is the only way to use evaluate_expression at the moment, you need to use the 3 letter acronyms for the names.
-[[[https://www.c-motion.com/v3dwiki/index.php?title=Segment_Default_Names|Default (Internal) Segment Names]]]