Statistical Aggregation Extension

Beyond the standard SPARQL functions, Apache Marmotta also supports the following additional aggregation functions when using the PostgreSQL backend:

mm:stddev(number) (statistics) returns the standard deviation of its arguments
mm:variance(number) (statistics) returns the variance of its arguments

The KiWi SPARQL module comes with its own these extensions:

PREFIX mm: <http://marmotta.apache.org/vocabulary/sparql-functions#>

Apache Marmotta Site