Aggregation functions

Aggregation functions are used to aggregate data items between different domain units

• count
• sum
• mean
• minimum
• maximum
• first
• last
• modus
• modus_weighted
• modus_count
• unique_count
• entropy
• average_entropy

• nth_element - nth element of an ascending sorted attribute
• nth_element_weighted - rank value based on the ascended weighted attribute
• rth_element - the r * (n-1)th elements of the ascending sorted attribute. N.B. use this operator for the median.

• standard deviance(sd)
• (var)iance
• (corr)elation
• (cov)ariance

• all
• any
• has_any

• pcount - count the number of entries of a relation in the related domain
• pcount_uint8 - is the pcount variant resulting in uint8 data item
• pcount_uint16 - is the pcount variant resulting in uint16 data item
• pcount_uint32 - is the pcount variant resulting in uint32 data item
• mapping_count - count the number of cells of a grid unit in another grid unit
• reg_count - count the non null values of an attribute towards a regional level

• min_index - index number of the minimum value of the non values

• max_index - index number of the maximum value of the non values

• as_unique_list

• frequency_table

• frequency_table_with_null