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--- visual3d:documentation:pipeline:expressions:array_and_matrix_functions [2024/06/19 12:49] – sgranger
+++ visual3d:documentation:pipeline:expressions:array_and_matrix_functions [2025/06/20 13:38] (current) – [Pose_4x4] wikisysop
@@ Line 1: / Line 1: @@
-===== arrays =====
+====== Array and Matrix Functions ======
-==== vector ====
+These array and matrix functions can be used anywhere Visual3D allows [[visual3d:documentation:pipeline:expressions:expressions_overview|expressions]] to be used.
-**vector**(a,b, etc)
+===== Arrays =====
-creates a vector of the number of components specified
+Arrays can be thought of as a 1-dimensional ordered list of numerical values.
-! create a metric signal with 2 components and one frame
+==== Vector ====
-[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**
-/expression=vector (1, metric::processed::vec2, link_model_based::original::rknee_angle)
-! /signal_types=
-! /signal_folder=original
-! /signal_names=
-! /result_types=derived
-! /result_folders=processed
-/result_name=test
-! /apply_as_suffix_to_signal_name=false
-**;**
-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:
+**Vector**(a,b, etc) - creates a vector of the number of components specified
-==== unit_vector ====
-**unit_vector (a, b, etc)** -- creates a unit vector of the number of components specified:
+<code>
-===== rotation matrices =====
+! Create a metric signal with 2 components and one frame
+Metric_Explicit
+! /RESULT_METRIC_FOLDER=PROCESSED
+/RESULT_METRIC_NAME=VEC2
+/METRIC_VALUE=2+3
+;
-==== rotation multiply ====
+! Create a vector containing a constant, a two dimensional metric and a 3 dimensional model based signal.
+Evaluate_Expression
+/EXPRESSION=vector (1, METRIC::PROCESSED::VEC2, LINK_MODEL_BASED::ORIGINAL::RKNEE_ANGLE)
+! /SIGNAL_TYPES=
+! /SIGNAL_FOLDER=ORIGINAL
+! /SIGNAL_NAMES=
+! /RESULT_TYPES=DERIVED
+! /RESULT_FOLDERS=PROCESSED
+/RESULT_NAME=TEST
+! /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=FALSE
+;
+</code>
-**rotation_multiply**(a,b)
+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.
-example: multiply two rotation signals
+==== List ====
-**evaluate_expression**
-/expression=rotation_multiply(rotation_inverse(rotation::original::pelvis_shifted_4x4),current_signal)
-/signal_types=rotation
-! /signal_folder=original
-! /signal_names=
-/result_types=rotation
-! /result_folders=processed
-/result_name=**_mult**
-/apply_as_suffix_to_signal_name=true
-**;**
-==== rotation inverse ====
-**rotation_inverse**(a)
+**list(a,b,etc)** - creates a list (column vector) of the number of rows specified.
-example: inverse of a 4x4 rotation signal or a 3x3 link_model_based rotation
+==== Unit_Vector ====
-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**
-/expression=rotation_inverse(rotation::original::pelvis_shifted_4x4)
-/signal_types=rotation
-! /signal_folder=original
-! /signal_names=
-/result_types=rotation
-! /result_folders=processed
-/result_name=**_inv**
-/apply_as_suffix_to_signal_name=true
-**;**
-\\
+**unit_vector (a, b, etc)** - creates a unit vector of the number of components specified.
-==== rotation transpose ====
+===== Rotation Matrices =====
-**rotation_transpose**(a)
+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]].
-example: transpose of a 3x3 link_model_based rotation signal
+==== Rotation Multiply ====
-**evaluate_expression**
-/expression=rotation_transpose(rotation::original::pelvis_shifted_4x4)
-/signal_types=rotation
-! /signal_folder=original
-! /signal_names=
-/result_types=rotation
-! /result_folders=processed
-/result_name=**_t**
-/apply_as_suffix_to_signal_name=true
-**;**
-==== pose_euler2rotation4x4 ====
-this was created for the shadow segments introduced in 2024.
+**Rotation_Multiply**(a,b) - Multiplies two rotation matrices
-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.
-pose_euler2rotation4x4(r_heel,0,0,0,123)
+Example: Multiply two ROTATION signals
+<code>
+Evaluate_Expression
+/EXPRESSION=ROTATION_MULTIPLY(ROTATION_INVERSE(ROTATION::ORIGINAL::PELVIS_SHIFTED_4x4),CURRENT_SIGNAL)
+/SIGNAL_TYPES=ROTATION
+! /SIGNAL_FOLDER=ORIGINAL
+! /SIGNAL_NAMES=
+/RESULT_TYPES=ROTATION
+! /RESULT_FOLDERS=PROCESSED
+/RESULT_NAME=_MULT
+/APPLY_AS_SUFFIX_TO_SIGNAL_NAME=TRUE
+;
+</code>
+==== 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
+<code>
+Evaluate_Expression
+/EXPRESSION=ROTATION_INVERSE(ROTATION::ORIGINAL::PELVIS_SHIFTED_4x4)
+/SIGNAL_TYPES=ROTATION
+! /SIGNAL_FOLDER=ORIGINAL
+! /SIGNAL_NAMES=
+/RESULT_TYPES=ROTATION
+! /RESULT_FOLDERS=PROCESSED
+/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**(a) - Creates the transposition of a rotation matrix.
+Example: Transpose of a 3x3 LINK_MODEL_BASED ROTATION signal
+<code>
+Evaluate_Expression
+/EXPRESSION=ROTATION_TRANSPOSE(ROTATION::ORIGINAL::PELVIS_SHIFTED_4x4)
+/SIGNAL_TYPES=ROTATION
+! /SIGNAL_FOLDER=ORIGINAL
+! /SIGNAL_NAMES=
+/RESULT_TYPES=ROTATION
+! /RESULT_FOLDERS=PROCESSED
+/RESULT_NAME=_T
+/APPLY_AS_SUFFIX_TO_SIGNAL_NAME=TRUE
+;
+</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 [[visual3d:documentation:modeling:segments:segment_overview#shadow_segments|shadow segments]] feature.
+Example: Create a rotation matrix for a shadow segment of the right heel
+<code>
+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]].