Help Matching Where Patterns Intersect

[usuallycwdillon]

I have a graph with events on a timeline and participants in events. I want to do some queries for statistics about how regularly participants attend, given that the events are irregularly spaced along the timeline.

Simplified: (:Person)-[:ATTENDS]->(:Event) and (:Event)-[:OCCURS]->(:Week) along with a time-tree of weeks (:Week)-[:NEXT_WEEK]-(:Week).

How can I isolate the weeks when an event occurs so that I can count the weeks between events?

For example, if I query MATCH p=( (:Event)-[:OCCURS]->(w:Week) ) WITH p MATCH (w)-[nw:NEXT_WEEK*]->(ww:Week)-[:OCCURS]-(:Event) RETURN length(nw) ORDER BY w the browser spins interminably. ...actually, I don't even get a response when I prepend it with PROFILE.

[usuallycwdillon]

I got a little closer with this query, but now it's giving me too every combination of distances between events.

MATCH (:Event)-[:OCCURS]->(w:Week) WITH DISTINCT w ORDER BY w.weekNumber WITH COLLECT(w.weekNumber) AS weeks
UNWIND weeks as wk
MATCH (p:Person)-[:ATTENDS]->(e:Event)-[:OCCURS]-(w:Week{weekNumber:wk})-[nw:NEXT_WEEK*]->(ww:Week)-[:OCCURS]-(ee:Event)-[:ATTENDS]-(pp:Person)
RETURN p, e, w, length(nw), ww, ee, pp

It looks like I'm getting the weeks between every combination of events instead of the number of weeks until the next event.

[michael_hunger]

Not 100% sure what you want to do. Do you want to get the spacing between particualar events? Or all events ( Events^2 ) ?

I would use shortestPath() for your var-length path.

MATCH (p:Person {id:$personId)-[:ATTENDS]->(e1:Event)-[:OCCURS]->(w1:Week),
(p)-[:ATTENDS]->(e2:Event)-[:OCCURS]->(w2:Week)
WHERE w1.week < w2.week
RETURN e1, e2, length(shortestPath( (w1)-[:NEXT*]->(w2) ) as distance