Scpecific request computing a raw

[Anthony]

I'm new Neo4j user and developper beginner.

I work on a graph that is composed of multiples parts.
Parts have subparts.
Each part and subparts have a weight.

How can i get the total weigth of a part composed by the weigth of
this part with the weigth of all subpart ?

I don't know neither Java nor Groovy.

Can you help me to choose the better way to begin ?

Thanks for your attention.

[Josh Adell]

I think you could do this with a Cypher query:

START part=node(123) // Or look it up in an index
MATCH p = part-[:HAS_SUB_PART]->subpart
RETURN SUM( EXTRACT (n in nodes(p) : n.weight ) )

I might be a bit shaky on the syntax, but all the pieces should be
there.

-- Josh

[Michael Hunger]

Probably as the number of parts is not limited (it's a tree) use an variable length path "*0.."

> START part=node(123) // Or look it up in an index

> MATCH p = part-[:HAS_SUB_PART*0..]->subpart

> RETURN SUM( EXTRACT (n in nodes(p) : n.weight ) )

[Josh Adell]

Ah yes. I thought it, I just didn't type it.

-- Josh

On Mar 2, 12:42 pm, Michael Hunger <michael.hun...@neotechnology.com>
wrote:

[Anthony]

Thanks for your reactivity.

The previous command help me but in my problem, there are
effectivities on relation.

Q1: How can I multiply effectivity with part weight ?

The ultimate goal should be to have : part weight = (subpart1.weight *
effectivity1) + (subpart2.weight * effectivity2) + ...

Q2: It's possible on cypher ?

One again, thanks.

[Michael Hunger]

How deep is your tree at maximum?

Michael

[Andres Taylor]

On Fri, Mar 2, 2012 at 6:34 PM, Josh Adell <josh....@gmail.com> wrote:

I think you could do this with a Cypher query:

START part=node(123)   // Or look it up in an index
MATCH p = part-[:HAS_SUB_PART]->subpart
RETURN SUM( EXTRACT (n in nodes(p) : n.weight ) )

We talked about this a few weeks ago, but it has not been implemented. You are trying to aggregate over a collection of elements, and not aggregate over sub graphs. And Cypher doesn't support that. :(

Andrés