Metric Signal Value At Event

Legacy Command

Metric_Signal_At_Event replaced the command Signal_Value_At_Event

Description

The value of the specified signal at the specified frame of data is stored as a metric.

• All components of the specified signal will be stored in the metric signal.
  • Since version 5: the user has the option to select an individual component
• If there are multiple occurrences of an EVENT, there will be multiple entries in the metric that is created.
• There is an option to calculate the mean and standard deviation for metrics that have multiple values.

Metric_Signal_Value_At_Event
/Result_Metric_Name=	The name of the resulting signal.
/Result_Metric_Folder=	The folder that will contain the resulting signal
/Signal_Types=	The type of signal to be evaluated
/Signal_Names=	The names of the signals to be evaluated
/Signal_Folder=	The name of the signal folder
/Event_Name=	The name of the event Label.
/Generate_Mean_And_Stddev=	If there are multiple occurences of the Event, the metric will contain multiple values.If Selecte the mean and standard deviation for the metric values will be computed.
/Append_To_Existing_Values=	(True or False) If the metric exists, the new values will be appended to the metric, retaining all of the previous values.
/Generate_Metric_Length_Metric=	(True or False) If the metric is a vector quantity (e.g. has 3 components), compute the magnitude of the vector.
/Retain_No_Data_Values=	(True or False) If the result is no_data, retain the value.

Example Value of a Target

This example calculates the value of the TARGET RFT1 at the Event_Label RON

Metric_Signal_Value_At_Event

/Result_Metric_Name=RFT1_ON

/Result_Metric_Folder=PROCESSED

/Signal_Types=TARGET

/Signal_Names=RFT1

/Signal_Folder=ORIGINAL

/Event_Name=RON

/Generate_Mean_And_Stddev=FALSE

/Append_To_Existing_Values=FALSE

/Generate_Metric_Length_Metric=FALSE

/Retain_No_Data_Values=TRUE

;

Note: In cases where there is NO_DATA at an event, you need to specify the parameter /Retain_No_Data_Values=TRUE should you want this included in the resulting signal.

Example Time at an Event

This example calculates the time of the Event_Label RON

Metric_Signal_Value_At_Event

/Result_Metric_Name=RON_TIME

/Result_Metric_Folder=PROCESSED

/Signal_Types=FRAME_NUMBERS

/Signal_Names=TIME

/Signal_Folder=ORIGINAL

/Event_Name=RON

/Generate_Mean_And_Stddev=FALSE

/Append_To_Existing_Values=FALSE

/Generate_Metric_Length_Metric=FALSE

/Retain_No_Data_Values=FALSE

;

Component Workaround

Since Metric_Signal_Value_At_Event outputs all three components, here is a workaround of the previous example that will output one component. Evaluate_Expression is used to create a signal with one component, the z component for RFT1. Then the Metric_Signal_Value_At_Event will calculate the value of the TARGET RFT1 at the Event_Label RON.

! RFT1 Z component
Evaluate_Expression 
/Expression=TARGET::ORIGINAL::RFT1::Z
/Result_Name=RFT1_Z
/Result_Type=DERIVED
/Result_Folder=ORIGINAL
; 

Metric_Signal_Value_At_Event
/Result_Metric_Name=RFT1_ON 
/Result_Metric_Folder=PROCESSED
/Signal_Types=DERIVED
/Signal_Names=RFT1_Z
/Signal_Folder=ORIGINAL
/Event_Name=RON
/Generate_Mean_And_Stddev=FALSE
/Append_To_Existing_Values=FALSE
/Generate_Metric_Length_Metric=FALSE
/Retain_No_Data_Values=TRUE
;

P2D Signals

Consider a P2D signal created using Global_Normalized_Signal_Mean.

The resulting signal has three components, an index, a mean signals, and a standard deviation signal

It is possible to compute the maximum value of the 3 components using Metric_Maximum

It isn't possible to directly identify the standard deviation at that index because it isn't possible to define an Event for a time normalized signal (e.g.it has no frame rate or time.

Without having an event you cannot get the value of a signal at that event using Metric_Signal_Value_At_Event

One solution, albeit a non-intuitive solution is to SORT (descending) the p2D signal by the second component (eg. the MEAN).

Evaluate_Expression

/EXPRESSION=SORT(P2D::TEST::LHIP_ANGLE, -1.0, 2)

! /SIGNAL_TYPES=

! /SIGNAL_FOLDER=ORIGINAL

! /SIGNAL_NAMES=

/RESULT_TYPES=P2D

/RESULT_FOLDERS=TEST_SORTED

/RESULT_NAME=LHIP_ANGLE_SORTED

!/APPLY_AS_SUFFIX_TO_SIGNAL_NAME=FALSE

';

For the resulting signal, the maximum value and the associated standard deviation will be in the first frame