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visual3d:documentation:pipeline:signal_commands:first_derivative [2024/06/19 12:53] sgrangervisual3d:documentation:pipeline:signal_commands:first_derivative [2024/11/11 14:05] (current) wikisysop
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-{{compute the first derivative at each point of a signal.+====== First Derivative ======
  
-the command can be edited via text editor or via dialogthe details on the command and the dialog are found below:+Compute the first derivative at each point of signal.
  
-|first_derivative.png  |\\ \\ \\ <code>\\ first_derivative\\ /signal_types=the type of signal to be evaluated\\ /signal_names=the name of the signal to be evaluated\\ /signal_folder=the name of the signal folder\\ /result_types=  the type of the resulting signal\\ /result_name= the name of the resulting signal \\ /result_folder= the name of the resulting folder \\ /result_suffix= the result is given the same name as the original signal with the suffix added\\ </code>  |+The command can be edited via text editor or via a dialogThe details on the command and the dialog are found below:
  
-the first and last data points become data_not_found (identified in the c3d file as a point reliability value of –1).+{{:First_Derivative.png}}
  
-===== calculation method =====+<code> 
 +First_Derivative 
 +/Signal_Types=The type of signal to be evaluated 
 +/Signal_Names=The name of the signal to be evaluated 
 +/Signal_Folder=The name of the signal folder 
 +/Result_Types The type of the resulting signal 
 +/Result_NameThe name of the resulting signal 
 +/Result_FolderThe name of the resulting folder 
 +/Result_SuffixThe result is given the same name as the original signal with the suffix added 
 +</code> 
  
-derivatives are calculated using finite difference algorithms.+The first and last data points become DATA_NOT_FOUND (identified in the C3D file as a POINT Reliability value of –1).
  
-given the signal:+==== Calculation Method ====
  
 +Derivatives are calculated using Finite Difference Algorithms.
 +
 +<code>
 +Given the signal:
 x(ti) for i=1, 2, ..., n x(ti) for i=1, 2, ..., n
-the first derivative is calculated using: 
  
-xdot(ti)= (x(ti+1)-x(ti-1))/( (ti+1)-(ti-1) ) +The first derivative is calculated using: 
-===== example: velocity of the centre of mass =====+xDot(ti)= (x(ti+1)-x(ti-1))/( (ti+1)-(ti-1) ) 
 +</code>
  
-the first_derivative command is useful for calculating the velocity of targets, landmarks, etc. since velocity is the first derivative of position. the following example calculates the velocity of the center of mass using the first_derivative command.+==== Example: Velocity of the Centre of Mass ==== 
 + 
 +The First_Derivative command is useful for calculating the velocity of targets, landmarks, etc. since velocity is the first derivative of position. The following example calculates the velocity of the center of mass using the First_Derivative command.
  
 <code> <code>
-given a signal representing the center of mass's position as follows: +Given a signal representing the center of mass's position as follows: 
-compute_model_based_data +Compute_Model_Based_Data 
-/result_name=com +/RESULT_NAME=COM 
-/function=model_cog +/FUNCTION=MODEL_COG 
-/segment+/SEGMENT
-/reference_segment+/REFERENCE_SEGMENT
-! /resolution_coordinate_system=lab +! /RESOLUTION_COORDINATE_SYSTEM=LAB 
-! /use_cardan_sequence=false +! /USE_CARDAN_SEQUENCE=FALSE 
-! /normalization=false +! /NORMALIZATION=FALSE 
-! /normalization_method+! /NORMALIZATION_METHOD
-! /normalization_metric+! /NORMALIZATION_METRIC
-! /negatex=false +! /NEGATEX=FALSE 
-! /negatey=false +! /NEGATEY=FALSE 
-! /negatez=false +! /NEGATEZ=FALSE 
-! /axis1=x +! /AXIS1=X 
-! /axis2=y +! /AXIS2=Y 
-! /axis3=z+! /AXIS3=Z
 ; ;
  
-the velocity of the center of mass can be computed as follows: +The velocity of the center of mass can be computed as follows: 
-first_derivative +First_Derivative 
-/signal_types=link_model_based +/SIGNAL_TYPES=LINK_MODEL_BASED 
-/signal_names=com +/SIGNAL_NAMES=COM 
-! /signal_folder=original +! /SIGNAL_FOLDER=ORIGINAL 
-/result_names=com_velocity +/RESULT_NAMES=COM_VELOCITY 
-/result_types=link_model_based +/RESULT_TYPES=LINK_MODEL_BASED 
-/result_folder=velocity +/RESULT_FOLDER=VELOCITY 
-! /result_suffix=+! /RESULT_SUFFIX=
 ; ;
 </code> </code>
  
  
-}}+
visual3d/documentation/pipeline/signal_commands/first_derivative.1718801587.txt.gz · Last modified: 2024/06/19 12:53 by sgranger