US Air Guitar. Structural Abstractions in Brains and Graphs « Aurelius. A graph database is a software system that persists and represents data as a collection of vertices (i.e. nodes, dots) connected to one another by a collection of edges (i.e. links, lines). These databases are optimized for executing a type of process known as a graph traversal. At various levels of abstraction, both the structure and function of a graph yield a striking similarity to neural systems such as the human brain. It is posited that as graph systems scale to encompass more heterogenous data, a multi-level structural understanding can help facilitate the study of graphs and the engineering of graph systems. Finally, neuroscience may foster a realization and appreciation of the various structural abstractions that exist within the graph.
The Neuron and the Vertex The human brain is believed to be composed of approximately 100 billion neurons and 1 quadrillion connections (1 quadrillion is 1000 trillion). The Area and the Motif The Region and the Subgraph Conclusion Acknowledgement. Connections in Time. Some relationships change over time. Think about your friends from high school, college, work, the city you used to live in, the ones that liked you ex- better, etc.
When exploring a social network it is important that we understand not only the strength of the relationship now, but over time. We can use communication between people as a measure. I ran into a visualization that explored how multiple parties where connected by communications in multiple projects. We’re going to reuse it to explore how multiple people interact with each other. So let’s make a network of 50 friends and connect them to each other multiple times. Think of it as people writing on your facebook wall. Let’s give our network a little something special. The code to create a relationship is pretty simple, we’ll use the Batch commands again and reference the nodes we create.
Let’s put it together to create our graph. We spent some time getting our data into our graph, now let’s get it all back out. Like this: Understanding the World using Tables and Graphs « Aurelius. March 22, 2012 by Marko A. Rodriguez The Table Perspective Each row represents the information of a particular individual. Each column represents the values of a property of all individuals. Finally, each entry represents a single value for a single property for a single individual. Given the person table above, various descriptive statistics can be calculated? Simple examples include: the average, median, and standard deviation of age (line 1),the average, median, and standard deviation of spending (line 3),the correlation between age and spending (i.e. do older people tend to spend more?
The Graph Perspective A graph (or network) is a structure composed of vertices (i.e. nodes, dots) and edges (i.e. links, lines). Load the friendship relationships as a two column numeric table (line 1-2).Generate an undirected graph from the two column table (line 3).Attach the person properties as metadata on the vertices (line 4-6). References Authors Like this: Like Loading... Disaster Area - Filed under 'neo4j' I recently helped add versioning support to Neo4j.rb . Versioning only works for Rails models at the moment. To add versioning to your model, you'll need include the Versioning module: How it works Versioning creates snapshots under a given rails model instance. Full snapshots Snapshots currently capture all the properties of an instance.
Let's look at an example: With version 1 of the driver, there are no links to any cars: With version 2, we link the driver to a sports car - a Porsche. Now, both the driver and the current version are linked to the Porsche. With version 3, we link the driver to a second car - a Ferrari. The driver, as well as the latest snapshot, are both linked to two cars - the Porsche and the Ferrarri. Working with a version To retrieve a snapshot, you'll need to call the version API. The snapshot object will respond to the exact same properties as those on instance. Reverting to a snapshot To revert to a particular version, simply call Max versions Gotchas Future improvements.
Neo4j « Romiko Derbynew's Blog. Bio4j blog | news and updates on bio4j. Hello everyone, I’m happy to announce a new set of features for our tool Bio4jExplorer plus some changes in its design. I hope this may help both potential and current users to get a better understanding of Bio4j DB structure and contents. Node & Relationship properties You can now check with Bio4jExplorer the properties that has either a node or relationship in the table situated on the lower part of the interface. Five columns are included: Name: property name Type: property type (String, int, float, String[], …) Indexed: either the property is indexed or not (yes/no) Index name: name of the index associated to this property -if there’s any Index name: type of the index associated to this property -if there’s any Node & Relationship Data source You can also see now from which source a Node or Relationship was imported, some examples would be Uniprot, Uniref, GO, RefSeq… Relationships Name property Get proteins (accession and names) associated to an interpro motif (limited to 10 results)
Marko A. Rodriguez. Neo4j Blog. Max De Marzi. Neo4j: NOSQL For the Enterprise.