Intoduction Oracle Parallel Graph Analytics (PGX) is a toolkit for graph analysis, both for running algorithms such as PageRank and for performing SQL-like pattern-matching against graphs. Extreme performance is offered through algorithm parallelization, and graphs can be loaded from a variety of sources such as flat files, SQL and NoSQL databases etc. So, in order to get a deeper feeling, …
Enabling the Green-Marl compiler for Parallel Graph Analytics in Oracle Big Data Lite VM
Recently, I began working with Parallel Graph Analytics (PGX) on my Oracle Big Data Lite (BDL) VM version 4.7.0.1. I was especially intrigued and curious about the capabilities of a PGX component called Green-Marl (GM), a domain-specific language specially designed for graph data analysis. It was stated to extend PGX’s capabilities and “implement algorithms with no limit”. Especially the last argument …
Streaming data from Raspberry Pi to Oracle NoSQL via Node-RED
Starting from version 4.2, Oracle NoSQL now offers drivers for Node.js and Python, in addition to the existing ones for Java, C, and C++; this is good news for data science people, like myself, since we are normally not accustomed to code in Java or C/C++. So, I thought to build a short demo project, putting into test both the …
Dynamically switch Keras backend in Jupyter notebooks
Recently, I was looking for a way to dynamically switch Keras backend between Theano and TensorFlow while working with Jupyter notebooks; I thought that there must be a way to work with multiple Keras configuration files, but this proved not to be the case. My issue was that, while I am mainly working with Theano, I wanted a quick and …
Workaround for disclosed af:query issue on ADF 12.2.1
While migrating ADF applications from 11 to 12 we stepped on a known bug in ADF 12.2.1 Bug 22469635 : AF:QUERY COMPONENT BUTTONS DON’T WORK WHEN “DISCLOSED” SET TO “FALSE” Since this is not resolved yet we needed a workaround. There were search criteria with disclosed=”false” in pages with rich layout that the user should expand it only if he …
sparklyr: a test drive on YARN
sparklyr is a new R front-end for Apache Spark, developed by the good people at RStudio. It offers much more functionality compared to the existing SparkR interface by Databricks, allowing both dplyr-based data transformations, as well as access to the machine learning libraries of both Spark and H2O Sparkling Water. Moreover, the latest RStudio IDE v1.0 now offers native support …
Nonlinear regression using Spark – Part 2: sum-of-squares objective functions
This post is the second one in a series that discusses algorithmic and implementation issues about nonlinear regression using Spark. In the previous post we identified a small window for contribution into Spark MLlib by adding methods for nonlinear regression, starting with the definition and implementation of a general nonlinear model. We remind the reader that regression is essentially an …
Classification in Spark 2.0: “Input validation failed” and other wondrous tales
Spark 2.0 has been released since last July but, despite the numerous improvements and new features, several annoyances still remain and can cause headaches, especially in the Spark machine learning APIs. Today we’ll have a look at some of them, inspired by a recent answer of mine in a Stack Overflow question (the question was about Spark 1.6 but, as …
How to evaluate R models in Azure Machine Learning Studio
Azure Machine Learning Studio is a GUI-based integrated development environment for constructing and operationalizing machine learning workflows. The basic computational unit of an Azure ML Studio workflow (or Experiment) is a module which implements machine learning algorithms, data conversion and transformation functions etc. Modules can be connected by data flows, thus implementing a machine learning pipeline. A typical pipeline in …
Installing the additional R packages in Oracle Big Data Lite VM 4.5.0
Oracle has just released version 4.5.0 of the Big Data Lite VM which, when it comes to R, still suffers from the issues we had pinpointed for the previous version 4.4.0 (and then some). The first attempt to install the additional packages fails with a ‘cannot open URL’ error: Fortunately, the warning about the proxy helps to locate the issue, …