Find the largest node of each segment in a series of paths

Neo4j Graph Platform Cypher
#1

I'm trying to divide different short chains according to the head and tail I want in a long chain, and find the max duration in the short chains.

E.g..
Long chain:
NA1 -> NA2 -> NA3 -> NA4 -> NB1 -> NB2 -> NB3 -> NB4 ->...

I want to check whether the max duration in each chain is the second node.
NA1 -> NA2 -> NA3 -> NA4
NB1 -> NB2 -> NB3 -> NB4
( N means node, A,b and the number are the attribute and each node has its own duration )

MATCH p = (A:Task{FROMLOCTYPE:"1"})-[:path*]->(b:Task{TOLOCTYPE:"4"})
WITH reduce(output = , n IN nodes(p) | output + n ) as tasks

But I'm stuck here and don't know how to check the maximum duration in each list.
Or do any operation in each list.

#2

Hi,
Could you please provide small dataset and the logic to break the big chain to smaller ones.

Regards
Vivek

#3

This is the sample for my data.

problem
problem1953×845 29.3 KB

Each node has FROMLOCTYPE,TOLOCTYPE,DURATION and Program.

I want to confirm that all nodes under the same program control, its longest time is in the second position (from B to C).

Thanks again for your reply.

#4

I inserted your sample data as below

A B 10 typeA
B C 12 typeA
C D 9 typeA
D A 2 typeA
A B 11 typeB
B C 19 typeB
C D 10 typeB
D A 5 typeB
A B 2 typeC
![image 690x282](upload://2QZQci5kzESaOhSTVpIZtkxivfr.png)

**and applied Query as **
unwind ["typeA","typeB","typeC"] as typeOf match p= (from:Chain)-[rel:CALLED{type:typeOf}]->(to:Chain) with rel.type as type, max(tointeger(rel.duration)) as maxDur return type, maxDur

**Output **

image
image930×243 1.62 KB

1 Like
#5

Hi, thank for your apply again.

Sorry my previous description was not clear enough.

I know how to find the max duration in one path.
By using

with max(n.attribute) as max_d
return (n.attribute:max_d)

But when I match to multiple path and try to find the max duration on each path.
I don't know how to find.
This is the data I use.

MATCH p = (A:Task{FROMLOCTYPE:"LOAD_PORT"})-[:wafer_path*]->(b:Task{TOLOCTYPE:"LOAD_PORT"})
return p limit 3

graph
graph930×853 46.7 KB

I can group nodes according to the classification I want.
But I ’m not sure how to query for the max duration in each group with cypher.

MATCH p = (A:Task{FROMLOCTYPE:"LOAD_PORT"})-[:wafer_path*]->(b:Task{TOLOCTYPE:"LOAD_PORT"})
WITH reduce(output = , n IN nodes(p) | output + n ) as nodeCollection

Sorry my previous description was not clear enough.
Thank you again for your reply

#6

Hi,

So you can see that my code is performing based on the type of relationship..
Do you want to find the query dynamically?

1 Like
#7

Hi, thank for your apply again.
Yes I want to find the query dynamically.

I think my problem should be when I find a bunch of lists.
How do I search these nodes at the same time.
A bit like how to find the maximum value of an array in a two-dimensional array.

I want to find the max number in each list I find.

Sorry my previous description was not clear enough.
Thank you again for your reply

#8

I am not very sure if below query is what you looking for
Dynamic type can be coded as below
match (from:Chain)-[rel:CALLED]->(to:Chain) with distinct rel.type as xyz unwind xyz as typeOf match p= (from:Chain)-[rel:CALLED{type:typeOf}]->(to:Chain) with rel.type as type, max(tointeger(rel.duration)) as maxDur return type, maxDur

If your requirement is different, then please frame your output and I will see if I am able to help you

1 Like
#9

Thanks for your reply.

This is helpful for me.
But if I don't want to use unwind ["typeA","typeB","typeC"] as typeOf.
How can I match the all type of the relation and unwind it?