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--- visual3d:documentation:pipeline:expressions:array_and_matrix_functions [2024/07/17 15:45] – created sgranger
+++ visual3d:documentation:pipeline:expressions:array_and_matrix_functions [2025/05/16 13:01] (current) – Cleaned up page formatting and added links. wikisysop
@@ Line 1: / Line 1: @@
 ====== Array and Matrix Functions ======
-==== Arrays ====
+These array and matrix functions can be used anywhere Visual3D allows [[visual3d:documentation:pipeline:expressions:expressions_overview|expressions]] to be used.
-=== Vector ===
+===== Arrays =====
-**Vector**(a,b, etc)
+Arrays can be thought of as a 1-dimensional ordered list of numerical values.
-creates a vector of the number of components specified
+==== Vector ====
+**Vector**(a,b, etc) - creates a vector of the number of components specified
+<code>
 ! Create a metric signal with 2 components and one frame
-[Metric_Explicit]
+Metric_Explicit
 ! /RESULT_METRIC_FOLDER=PROCESSED
 /RESULT_METRIC_NAME=VEC2
 /METRIC_VALUE=2+3
-**;**
+;
 ! Create a vector containing a constant, a two dimensional metric and a 3 dimensional model based signal.
-**Evaluate_Expression**
+Evaluate_Expression
 /EXPRESSION=vector (1, METRIC::PROCESSED::VEC2, LINK_MODEL_BASED::ORIGINAL::RKNEE_ANGLE)
 ! /SIGNAL_TYPES=
@@ Line 25: / Line 29: @@
 /RESULT_NAME=TEST
 ! /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=FALSE
-**;**
+;
+</code>
 The resulting signal will have the first three columns (one for the constant, one for the vector of 2 components) buffered to the number of frames of RKNEE_ANGLE by replicating the first frame.
-=== List ===
-**list(a,b,etc)** -- creates a list (column vector) of the number of rows specified:
+==== List ====
-=== Unit_Vector ===
-**unit_vector (a, b, etc)** -- creates a unit vector of the number of components specified:
+**list(a,b,etc)** - creates a list (column vector) of the number of rows specified.
-==== Rotation Matrices ====
-=== Rotation Multiply ===
+==== Unit_Vector ====
-**Rotation_Multiply**(a,b)
+**unit_vector (a, b, etc)** - creates a unit vector of the number of components specified.
+===== Rotation Matrices =====
+Rotation matrices are used throughout Visual3D because they can entirely contain the information regarding a segment's [[visual3d:documentation:kinematics_and_kinetics:pose_estimation|pose]].
+==== Rotation Multiply ====
+**Rotation_Multiply**(a,b) - Multiplies two rotation matrices
 Example: Multiply two ROTATION signals
-**Evaluate_Expression**
+<code>
+Evaluate_Expression
 /EXPRESSION=ROTATION_MULTIPLY(ROTATION_INVERSE(ROTATION::ORIGINAL::PELVIS_SHIFTED_4x4),CURRENT_SIGNAL)
 /SIGNAL_TYPES=ROTATION
@@ Line 47: / Line 59: @@
 /RESULT_TYPES=ROTATION
 ! /RESULT_FOLDERS=PROCESSED
-/RESULT_NAME=**_MULT**
+/RESULT_NAME=_MULT
 /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=TRUE
-**;**
+;
-=== Rotation Inverse ===
+</code>
-**Rotation_Inverse**(a)
+==== Rotation Inverse ====
+**Rotation_Inverse**(a) - Calculates the inverse of a rotation matrix
 Example: Inverse of a 4x4 ROTATION signal or a 3x3 LINK_MODEL_BASED ROTATION
-A good description of the inverse of a ROTATION signals can be found [[[http://www.info.hiroshima-cu.ac.jp/~miyazaki/knowledge/teche0053.html|here]]]
-**Evaluate_Expression**
+<code>
+Evaluate_Expression
 /EXPRESSION=ROTATION_INVERSE(ROTATION::ORIGINAL::PELVIS_SHIFTED_4x4)
 /SIGNAL_TYPES=ROTATION
@@ Line 63: / Line 78: @@
 /RESULT_TYPES=ROTATION
 ! /RESULT_FOLDERS=PROCESSED
-/RESULT_NAME=**_INV**
+/RESULT_NAME=_INV
 /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=TRUE
-**;**
+;
-\\
+</code>
+**Note**: A good description of the inverse of a ROTATION signals can be found [[http://www.info.hiroshima-cu.ac.jp/~miyazaki/knowledge/teche0053.html|here]]
-=== Rotation Transpose ===
+==== Rotation Transpose ====
-**Rotation_Transpose**(a)
+**Rotation_Transpose**(a) - Creates the transposition of a rotation matrix.
 Example: Transpose of a 3x3 LINK_MODEL_BASED ROTATION signal
-**Evaluate_Expression**
+<code>
+Evaluate_Expression
 /EXPRESSION=ROTATION_TRANSPOSE(ROTATION::ORIGINAL::PELVIS_SHIFTED_4x4)
 /SIGNAL_TYPES=ROTATION
@@ Line 81: / Line 98: @@
 /RESULT_TYPES=ROTATION
 ! /RESULT_FOLDERS=PROCESSED
-/RESULT_NAME=**_T**
+/RESULT_NAME=_T
 /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=TRUE
-**;**
+;
-=== Pose_Euler2Rotation4x4 ===
+</code>
+==== Pose_4x4 ====
+**Pose_4x4(a,0,0,0,123)** - Creates a 4x4 rotation signal based on signal "a" with the translation of the origin (0,0,0) and the orientation defined by Euler angles with the Euler sequence 123.
+This function was created in support of the [[id=visual3d:documentation:modeling:segments:segment_overview#shadow_segments|shadow segments]] feature.
-This was created for the Shadow segments introduced in 2024.
+Example: Create a rotation matrix for a shadow segment of the right heel
-Create a 4x4 Rotation from the Visual3D pose of a segment, with the translation of the origin represented in any coordinate system, and the orientation defined by Euler angles and the Euler sequence.
+<code>
-POSE_EULER2ROTATION4X4(R_HEEL,0,0,0,123)
+POSE_4X4(R_HEEL,0,0,0,123)
+</code>
+===== See Also =====
+Go back to see other [[visual3d:documentation:pipeline:expressions:expressions_overview#functions|Expression functions]].