DATA ANALYSIS PACKAGE SYMBOL
PartitionAssociation

PartitionAssociation[assoc,n]
partitions the association assoc into nonoverlapping subassociations of length n and returns a new association.
PartitionAssociation[assoc,n,d]
generates subassociations with offet d.
PartitionAssociation[assoc,n,d,i]
generates subassociations with offet d and the keys of the resulting association are generated from item number i of the partition group.