The Statistic Of Expression Feature calculates one or more statistics on the result of a mathematic expression that is calculated against past events. The mathematic expression can include Subject attributes that are numeric or integer. Each statistic is output to a Feature with its own name.
For Example:
- The average (string) length of auction listing description
- The average and minimum (string) length of a payment reference
Configuration
-
Feature Name
The "dictionary" name under which the feature value will be stored. -
Expression
A Query-Language expression that will be evaluated against past events.
Note
- The expression should result in a numeric value.
- Into Features
- Time Between can calculate multiple statistics from a single configuration and output them to the Feature Names given. Simply fill in the Feature Name for the required statistics, any that are not required can be left blank.
Note
- There are multiple Feature Names generated, a Feature Name must be given to each of the required statistics.
Optional Configuration
- Default Value
A value that can be assigned to the feature if the attributes to calculate the features are not present. - Scope
Can be used to extend the event search from the local node, to all nodes within the same organization all the way to all across customers (global). - For Events
Provides a way of filtering past events based on their type. - Condition
A Query-Language filter that can be used to refine Features for specific use cases. - Time Window
Can be used to limit the Feature calculation to a specific time period/window. e.g 1 week. - Starting ...
Can be used to remove recent events from Feature calculation.
Use Case 1
The average (string) length of auction listing description. New auction listings could then be checked to see if they are less than half the average length for a user over the last 3 months to detect anomolous behaviour:
len(auction_lising.description) < (outcome['CHAMPION'].features.general['avg_description_len_3mths'] * 0.5)
Implementing In The Feature Editor
