Find Correlations in Vectors of symbols Given a set of vectors, lets say that each coordinate is populated from an alphabet (meaning set of symbols, numbers, etc) (particular or shared alphabets are indistinct). 

Is there any standard procedure for performing the following task ?  

Look for sets of positions that "make the same choice" in several vectors.

That means: a subset of indices where, when we project to just those indices, there's some value that's taken on by many of the vectors.

An example:

Input                 
[0,-,0]
[0,+,+]
[+,+,+]
[0,0,0]
[-,+,+]

Output

2 coordinates involved ( 2 and 3), appearing in 3 vectors: x2=+ and x3=+
1 coordinate involved (1), appearing in 2 vectors:  x1=0
A possible solution would be generating (in Apriori terms) a "transaction" that contains indexed symbols and mine that for frequent itemsets.