====== Metric StdDev ======
====Overview====
This metric signal is used to compute the Standard Deviation of a Signal and store the value as a metric. It can be found in the **Pipeline Workshop** under **Metric**.
====Pipeline Command====
The command syntax is as follows:
Metric_StdDev
! /RESULT_METRIC_FOLDER=PROCESSED
/RESULT_METRIC_NAME=
! /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=FALSE
/SIGNAL_TYPES=
! /SIGNAL_FOLDER=ORIGINAL
! /SIGNAL_NAMES=
! /COMPONENT_SEQUENCE=
/EVENT_SEQUENCE=
/EXCLUDE_EVENTS=
! /GENERATE_MEAN_AND_STDDEV=TRUE
! /GENERATE_MEAN_AND_STDDEV_ACROSS_SUBJECTS=FALSE
! /APPEND_TO_EXISTING_VALUES=FALSE
;
====Command Parameters====
The following table shows the command parameters seen above and their descriptions:
|**RESULT_METRIC_FOLDER**|**The name of the result signal folder**|
|**RESULT_METRIC_NAME**|**The name of the result signal**|
|**APPLY_AS_SUFFIX_TO_SIGNAL_NAME**|**Apply suffix to processed signals**|
|**SIGNAL_TYPES**|**Types of signals to be processed**|
|**SIGNAL_NAMES**|**Names of signals to be processed**|
|**COMPONENT_SEQUENCE**|**Which component of the signal will be used for statistical analysis of the sequence.**|
|**EVENT_SEQUENCE**|**A list of events (separated by “+” signs). For example, LHS+RTO**|
|**EXCLUDE_EVENTS**|**This Event Sequence must not be during the sequence requested. For example, LTO_RHS**|
|**GENERATE_MEAN_AND_STDDEVE**|**(True or False)Generate the mean and standard deviation for all of the metrics created**|
|**GENERATE_MEAN_AND_STDDEV_ACROSS_SUBJECTS**|**(True or False)Generate the mean and standard deviation for all of the metrics created across all trials**|
|**APPEND_TO_EXISTING_VALUES**|**(True or False)Append this list of metrics to an existing metric of the same result name**|
====Dialog====
The command can be edited in a text editor or in a dialog form. To edit in the dialog pop up form either click on the **Edit** button in the pipeline workshop or double-click on the pipeline command. The dialog is shown below.
{{:MetricStdDevDlg.png}}
The dialog box allows you to assign values to the command parameters outlined above.
==== Example ====
In the following example, compute the Standard Deviation of the signal HANDSPEED
Metric_StdDev
! /RESULT_METRIC_FOLDER=PROCESSED
/RESULT_METRIC_NAME=Handspeed_SD
! /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=FALSE
/SIGNAL_TYPES=DERIVED
/SIGNAL_FOLDER=PROCESSED
/SIGNAL_NAMES=HANDSPEED
/COMPONENT_SEQUENCE=ALL
/EVENT_SEQUENCE=FRAME1+GO
/EXCLUDE_EVENTS=MAX_SPEED
! /GENERATE_MEAN_AND_STDDEV=TRUE
! /GENERATE_MEAN_AND_STDDEV_ACROSS_SUBJECTS=FALSE
! /APPEND_TO_EXISTING_VALUES=FALSE
;
|**Metric_StdDev** | | |
|**/RESULT_METRIC_NAME=** |_SD |The name of the metric signal created |
|**/APPLY_AS_SUFFIX_TO_SIGNAL_NAME=** |True |Specify the metric name to be the ORIGINAL signal plus a SUFFIX |
|**/RESULT_METRIC_FOLDER=** |PROCESSED | |
|**/SIGNAL_TYPES=** |DERIVED | |
|**/SIGNAL_NAMES=** |HANDSPEED |Specify the Signal to be used |
|**/SIGNAL_FOLDER=** |PROCESSED | |
|**/SIGNAL_COMPONENTS=** |ALL_COMPONENTS |Specify the Signal components to be used (e.g. X, Y, Z or 0, 1, 2 etc) |
|**/[[Visual3D:Documentation:C3D_Signal_Types:EVENT_LABEL_Data_Type#Event_Sequence|EVENT_SEQUENCE]]=** |FRAME1 + GO |Specify the sequence of Events. Any number of Events can be entered (separated by +). This specific sequence of events must be true for a metric to be computed. The metric is computed from the first event in the sequence to the last event in the sequence|
|**/[[Visual3D:Documentation:C3D_Signal_Types:EVENT_LABEL_Data_Type#Exclude_Events|EXCLUDE_EVENTS]]=** |MAX_SPEED |If this event occurs before the first and last event, do not computed a metric |
|**/[[Visual3D:Documentation:Pipeline:Metric_Commands:SEQUENCE_PERCENT_START|SEQUENCE_PERCENT_START]]=**|Within the event sequence specify the beginning of the range as a percent| |
|**/[[Visual3D:Documentation:Pipeline:Metric_Commands:SEQUENCE_PERCENT_START|SEQUENCE_PERCENT_END]]=** |Within the event sequence specify the end of the range as a percent | |
|**/GENERATE_MEAN_AND_STDDEV=** |TRUE |Generate the mean and standard deviation of this metric across ranges and files |
|**/APPEND_TO_EXISTING_VALUES==** |FALSE |Do not Add these metric values to an existing metric |
|**;** | | |
====Stride Time STD Deviation====
Here the **Metric StdDev==== command and **Metric Time Between Events** are used together to find the std deviation in the time between right heel strikes.
First gait events must be defined:
Automatic_Gait_Events
! /FRAME_WINDOW=8
! /USE_TPR=TRUE
! /TPR_EVENT_INSTANCE=1
;
Next **Metric Time Between Events** is used to compute the time between each RHS (which is being used here as stride time):
Metric_Time_Between_Events
/RESULT_METRIC_NAME=Stride_Time
! /RESULT_METRIC_FOLDER=PROCESSED
/EVENT_SEQUENCE=RHS+RHS
/EXCLUDE_EVENTS=
! /SCALE_FACTOR=1
/GENERATE_MEAN_AND_STDDEV=FALSE
! /APPEND_TO_EXISTING_VALUES=FALSE
;
Finally, **Metric StdDev** is used to find the std deviation in stride time across all trials:
Metric_StdDev
/RESULT_METRIC_FOLDER=PROCESSED
/RESULT_METRIC_NAME=Stride_Time_SD
! /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=FALSE
/SIGNAL_TYPES=METRIC
/SIGNAL_FOLDER=PROCESSED
/SIGNAL_NAMES=Stride_Time
! /COMPONENT_SEQUENCE=
/EVENT_SEQUENCE=
/EXCLUDE_EVENTS=
! /GENERATE_MEAN_AND_STDDEV=TRUE
! /GENERATE_MEAN_AND_STDDEV_ACROSS_SUBJECTS=FALSE
! /APPEND_TO_EXISTING_VALUES=FALSE
;
The results should look similar to below:
{{:visual3d:documentation:pipeline:metric_commands:stride_stddev.png?600|}}