Max_index

aggregation-functions max_index

syntax

  • max_index(a)
  • max_index(a, relation)

definition

  • max_index(a) results in a parameter with the index numbers of the maximum value of the non null values of attribute a.
  • max_index(a, relation) results in an attribute with the index numbers of the maximum values of the non null values of attribute a, grouped by relation. The domain-unit of the resulting attribute is the values-unit of the relation.

description

The max_index function is not defined for string data items.

applies to

  • attribute a with Numeric, Point or boolean value type.
  • relation with value type of the group CanBeDomainUnit

conditions

The values unit of the resulting data item should be the domain unit of argument a.

since version

7.184

example 

parameter<Cit>  max_index_NrInh                := max_index(City/NrInhabitants); result = 0
attribute<City> max_index_NrInhRegion (Region) := max_index(City/NrInhabitants, City/Region_rel);
City/NrInhabitants City/Region_rel
550 0
525 1
300 2
500 1
200 3
175 null
null 3

domain City, nr of rows = 7

max_index_NrInhRegion
0
1
2
4
null

domain Region, nr of rows = 5

see also