Aggregation

RiskScape can aggregate individual results into more meaningful information. For example, instead of reporting each individual damaged building, RiskScape can report a total count of damaged buildings.

To produce an aggregated result, you need to use an aggregation expression, which has the form:

aggregation-function(attribute-to-aggregate) as new-name

For example, max(hazard) as Max_flood_depth or sum(consequence.loss) as Total_loss are simple aggregation expressions. Refer to RiskScape expression language for more details on what expressions are.

Aggregation expressions are used in the group pipeline step. The group step also specifies the attribute to group the results by. For example, to see the results broken down based on a building’s construction type, you might group by the exposure.construction attribute.

Results can also be aggregated spatially, such as producing a total count for each regional territory. Spatial aggregation is done by using an area-layer in your model and then grouping by area.name.

Built-in aggregation functions

The following functions are built into RiskScape:

  • count

  • max

  • mean

  • median

  • min

  • mode

  • percentile

  • stddev (Standard Deviation)

  • sum

For more information on a particular function, enter the riskscape function info <function-name> command.