apoc.neighbors.byhop.count

Procedure APOC Core

apoc.neighbors.byhop.count(node, rel-direction-pattern, distance) - returns distinct nodes of the given relationships in the pattern at each distance, can use '>' or '<' for all outgoing or incoming relationships

Signature

apoc.neighbors.byhop.count(node :: NODE?, types =  :: STRING?, distance = 1 :: INTEGER?) :: (value :: LIST? OF ANY?)

Input parameters

Name Type Default

node

NODE?

null

types

STRING?

distance

INTEGER?

1

Output parameters

Name Type

value

LIST? OF ANY?

Usage Examples

The examples in this section are based on the following sample graph:

MERGE (mark:Person {name: "Mark"})
MERGE (praveena:Person {name: "Praveena"})
MERGE (joe:Person {name: "Joe"})
MERGE (lju:Person {name: "Lju"})
MERGE (michael:Person {name: "Michael"})
MERGE (emil:Person {name: "Emil"})
MERGE (ryan:Person {name: "Ryan"})

MERGE (ryan)-[:FOLLOWS]->(joe)
MERGE (joe)-[:FOLLOWS]->(mark)
MERGE (mark)-[:FOLLOWS]->(emil)
MERGE (michael)-[:KNOWS]-(emil)
MERGE (michael)-[:KNOWS]-(lju)
MERGE (michael)-[:KNOWS]-(praveena)
MERGE (emil)-[:FOLLOWS]->(joe)
MERGE (praveena)-[:FOLLOWS]->(joe)

This procedure computes a node’s neighborhood at multiple hop counts.

The following returns the number of people that Emil KNOWS and the number that have FOLLOWS relationships to him, at up to 3 hops:

MATCH (p:Person {name: "Emil"})
CALL apoc.neighbors.byhop.count(p, "KNOWS|<FOLLOWS", 3)
YIELD value
RETURN value
Table 1. Results
value

[2, 3, 1]

And as expected we have a count of 2 at level 1, 3 at level 2, and 1 at level 3.

We could even turn that list of numbers into a map with the key being the number of hops and the value the neighborhood size. The following query shows how to do this using the apoc.map.fromLists function:

MATCH (p:Person {name: "Emil"})
CALL apoc.neighbors.byhop.count(p, "KNOWS|<FOLLOWS", 3)
YIELD value
RETURN apoc.map.fromLists(
         [value in range(1, size(value)) | toString(value)],
         value) AS value
Table 2. Results
value

{1: 2, 2: 3, 3: 1}

If we also want to know which nodes are in our neighborhood, we can do that as well. See apoc.neighbors.byhop.

More documentation of apoc.neighbors.byhop.count