mneedham

Learning dem graph gists

Awesome

Something something, graph gist

mneedham

neo4j-meetup.core> (take 1 (map (fn [x] (println (str "printing..." x))) (range)))
(printing...0
printing...1
printing...2
printing...3
printing...4
printing...5
printing...6
printing...7
printing...8

mneedham

(defn offsets [perpage]
  (map #(* perpage %) (range)))

(defn events
  [{perpage :perpage offset :offset orderby :orderby}]
  (->> (client/get
        (str "https://api.meetup.com/2/events?page=" perpage
             "&offset=" offset
             "&orderby=" orderby
             "&status=upcoming,past&"

mneedham

MATCH (meetup)-[:INITIALLY_RSVPD]->(rsvp1 {response: "yes"})-[:NEXT]->(rsvp2 {response: "no"})-[:TO]->(event)
MATCH (event)-[:HAPPENED_ON]->(ed1)<-[:HAS_DAY]-(em1)<-[:HAS_MONTH]-(ey1)
MATCH (rsvp1)-[:HAPPENED_ON]->(d1)<-[:HAS_DAY]-(m1)<-[:HAS_MONTH]-(y1)
MATCH (rsvp2)-[:HAPPENED_ON]->(d2)<-[:HAS_DAY]-(m2)<-[:HAS_MONTH]-(y2)
MATCH path = (d2)<-[:NEXT*]-(d1)
RETURN meetup.name, 
       event.name, 
       ed1.day + "/" +  em1.month + "/" + ey1.year AS eventDate,
       d1.day + "/" +  m1.month + "/" + y1.year AS initialYes,
       d2.day + "/" +  m2.month + "/" + y2.year AS changedToNo,

mneedham

= Rounding a float value to decimal places
:neo4j-version: 2.1.0-RC1
:author: Mark Needham
:twitter: @markhneedham

Every now and then I find myself dealing with float values such as the following:

[source,cypher]
----
RETURN toFloat("12.336666") AS value

mneedham

How to create relatonships between elements in a collection

This GraphGist answers a Stackoverflow question.

Creating A Sample User Graph

We want to create a social network, and have to connect some people. Let’s do that in two steps.

mneedham

library(Rneo4j)
library(ggplot2)

graph = startGraph("http://localhost:7474/db/data/")

query = "MATCH (group1:Group), (group2:Group)
         WHERE group1 <> group2
	       OPTIONAL MATCH path = (group1)<-[:MEMBER_OF]-()-[:MEMBER_OF]->(group2)

         WITH group1, group2, COLLECT(path) AS paths

mneedham

Modelling time-varying financial exposures in Neo4j

Answer to this Stackoverflow Question

Question

How would one model this kind of data in Neo4j?:

> HOLDINGS
   Portfolio                         Holding    Instrument       Date BALANCE.USD

mneedham

The World Cup Graph

The football World Cup is just under a week away so I thought we deserved a World Cup graph for the occasion. It’s still a work in progress but here’s what I’ve got so far.

mneedham

The World Cup Graph

Initial Data Setup