Category Archives: Java

Building a Chat Bot in Neo4j Part 3

In part one, we learned to listen to our users, in part two we began learning how to talk back. Before we go any further in to the stored procedure, how about we build a little front end to show off the work we’ve done so far on this proof of concept? That will also make things easier to test out and let us get into the mindset of the user. There are a ton of options here, lots of folks like Spring and Spring Boot. Others are more hipsters and into Micronaut. I am even more of a hipster and prefer to use Jooby, but it doesn’t really matter. We’ll be using Cypher, the Neo4j Drivers and the Stored Procedures we build along the way so technically you can do this in just about any language.
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Building a Chat Bot in Neo4j Part 2

In part one our this building a chatbot series, we figured out how to use OpenNLP to “hear” what a user is saying and figure out both their intent and any entities they may have mentioned. Today we’re going to learn how to use Neo4j to talk back… like an impudent child.

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Building a Chat Bot in Neo4j

Last year eBay built a chatbot using Neo4j. Unfortunately we have grown so big I didn’t get a chance to work on that project and kinda feel left out. So I decided I’m going to build my own chatbot with Neo4j. As usual I’ve never done this before, have very little idea what I’m doing, have no team, and have barely any time to get this done. So with those disclaimers out of the way, let’s see what we can do.
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Testing APOC inside your Stored Procedures

The Awesome Procedures on Cypher (APOC) plugin is packed with goodies to make your life working with Neo4j easier. Sometimes you want to use these goodies in your own stored procedures…and you want to be able to test them. So how do we go about doing that exactly?
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Parallel K-Hop Counts

As a foreigner I was a little perplexed the first time I went to IHOP. You are served a stack of pancakes 3-5 high. How do you eat them? Do you pour syrup over the top and cut down through all the layers and eat them that way… or do you unstack them, pour syrup over each one and eat one at a time? If you are American, you eat them stacked. If you see someone eat them one at a time, you know they are shape-shifting lizard people. But doesn’t that mean the bottom layers are dry and don’t get any butter or syrup on them? Well you would think, but Americans are an ingenious people and they found a way to fix that problem. More syrup, more and more, and then a bit more to be sure… and a side of bacon. Now that you know all about IHOP, let’s switch gears to KHOP. Let’s say you wanted to find out how many nodes there were k-hops away from a starting node. What would be the best way to do that?

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Network Routing in Neo4j

People use Neo4j to manage enterprise architectures all the time. If you haven’t seen this presentation from Thomas Lawrence from Amadeus, then you owe it to yourself to watch it. But what about lower level networks? Can we use Neo4j to model routing in a physical network? Of course we can, and today I’ll show you how.

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Calculating the best Rail Road paths in Neo4j

Did you know that Chicago is the most important railroad center in North America? Chicago has more lines of track radiating in more directions than from any other city. The windy city has long been the most important interchange point for freight traffic between the nation’s major railroads and it is the hub of Amtrak, the intercity rail passenger system. You may not realize it, but railroad tracks and graph theory have a history together. Back in the mid 1950s the US Military had an interest in finding out how much capacity the Soviet railway network had to move cargo from the Western Soviet Union to Eastern Europe. This lead to the Maximum Flow problem and the Ford–Fulkerson algorithm to solve it.

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Neo4j Stored Procedures for Devs that don’t know Java (yet)

When I joined Neo4j, I didn’t know how to write Java. I was a SQL developer who knew some Ruby and that’s about it. Luckily I had Michael Hunger, Stefan Armbruster, David Montag and others to help me out. I realize however that you may not be so lucky. So today I’m going to share with you a set of slides to help you start you on your journey of using the full power of Neo4j.
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Dynamic Rule Based Decision Trees in Neo4j – Part 4

So far I’ve only showed you how to traverse a decision tree in Neo4j. The assumption being that you would either create the rules yourself from expert knowledge or via an external algorithm. Today we’re going to add an algorithm to build a decision tree (well a decision stream) right into Neo4j. We will simply pass in the training data and let it build the tree for us. If you are reading this part without reading parts one, two, and three, you should because this builds on what we learned along the way.

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Dynamic Rule Based Decision Trees in Neo4j – Part 3

At Graph Connect this year I did a short lightning talk on building Decision Trees using Neo4j. The slides are up and down below, the video is up. After the talk, someone asked, “What if we don’t know all the facts ahead of time?”. They wanted to be able to step through the tree and ask for the facts as needed at each step. So today we’re going to see how to do that.
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