Statistics Example 1

This example will time normalize a signal (in this case Knee Flexion Angle) between events (RHS to RHS) for Right Knee angles and (LHS to LHS) for Left Knee angles, and compute a GLOBAL mean and Standard Deviation. A meta-command will be used.

Add the Global_Normalized_Signal_Mean command to the pipeline. Double click on the command to launch the dialog.

Select the RKNEE_ANGLE Signal and the event sequence (e.g RHS to RHS) and select Add A New Signal

Select the LKNEE_ANGLE Signal and the event sequence (e.g LHS to LHS) and select Add A New Signal

Enter in the P2D Result Signal Name and the select Create Standard Deviation Button

When you select OK the text representation of the command should be as follows:

Global_Normalized_Signal_Mean
/SIGNAL_TYPES=LINK_MODEL_BASED+LINK_MODEL_BASED
/SIGNAL_NAMES=RKNEE_ANGLE+LKNEE_ANGLE
/SIGNAL_FOLDER=ORIGINAL+ORIGINAL
/SIGNAL_COMPONENTS=X+X
/START_LABEL=
/END_LABEL=
/EVENT_SEQUENCE= RHS+RHS++LHS+LHS
! /EXCLUDE_EVENTS=
/RESULT_NAME=KNEE_FLEXION
! /RESULT_FOLDER=ORIGINAL
/NORMALIZE_POINTS=101
/CREATE_STANDARD_DEVIATION=TRUE
! /CALCULATE_PER_FILE=FALSE
;

Note: If CALCULATE_PER_FILE=FALSE. Signals from all active files are used to compute the mean

Note: If CALCULATE_PER_FILE=TRUE. The mean value is computed for Signals from each active files. The global mean value is then the mean value of the mean values.

Note: That the Output signal is a P2D Signal, which is associated with every file. The resulting signal, therefore, is stored in the GLOBAL_WORKPACE

The Meta-Command Create_Global_Means_For_Left_Right will be used for processing all 3 components of a number of model based signals using one pipeline command. Let the original cmo file contain the following signals:

RANKLE_ANGLE

RKNEE_ANGLE

RHIP_ANGLE

LANKLE_ANGLE

LKNEE_ANGLE

LHIP_ANGLE

Let the events for heel strike be labeled LHS and RHS and that mean signal should be computed from heel strike to heel strike.

The Pipeline script for the Create_Global_Means_For_Left_Right meta-command is below:

Create_Global_Means_For_Left_Right
/TYPE=ANGLE
/JOINTS=ANKLE+KNEE+HIP
/START_EVENT=HS
/END_EVENT=HS
;

The following should be cut and pasted into the Create_Global_Means_For_Left_Right.v3m Meta_Command folder which should be placed within the Plugins folder.

! BEGIN_META
! META_CMD_NAME=Create_Global_Means_For_Left_Right
! META_PARAM=    TYPE  :   string ::yes
! META_PARAM=    JOINTS  :   string ::yes
! META_PARAM=    START_EVENT  :   string ::yes
! META_PARAM=    END_EVENT  :   string ::yes
! END_META

! Create a Global_Normalized_Signal_Mean event for left and right
! sides with common labels (e.g. RHS and LHS)

For_Each
/ITERATION_PARAMETER_NAME=INDEX1
/ITEMS=::JOINTS
;

For_Each
/ITERATION_PARAMETER_NAME=INDEX2
/ITEMS=X+Y+Z
;
 
Global_Normalized_Signal_Mean
/SIGNAL_TYPES=LINK_MODEL_BASED+LINK_MODEL_BASED
/SIGNAL_NAMES=R&::INDEX1&_&::TYPE+L&::INDEX1&_&::TYPE
/SIGNAL_FOLDER=ORIGINAL+ORIGINAL
/SIGNAL_COMPONENTS=::INDEX2+::INDEX2
/START_LABEL=R&::START_EVENT+L&::END_EVENT
/END_LABEL=R&::START_EVENT+L&::END_EVENT
! /EVENT_SEQUENCE=
! /EXCLUDE_EVENTS=
/RESULT_NAME=::INDEX1&_&::TYPE&_&::INDEX2
! /RESULT_FOLDER=ORIGINAL
! /NORMALIZE_POINTS=101
! /CREATE_STANDARD_DEVIATION=FALSE
! /CALCULATE_PER_FILE=FALSE
;

End_For_Each
/ITERATION_PARAMETER_NAME=INDEX2
;

End_For_Each
/ITERATION_PARAMETER_NAME=INDEX1
;