Monday, March 27, 2017

Machine learning: Getting started with random forests in R

According to Gartner, machine learning is on top of the hype cycle at the peak of inflated expectations. There is a lot of misunderstanding about what machine learning actually is and what it can be done with it.

Machine learning is not as abstract as one might think. If you want to get value out of known data and do predictions for unknown data, the most important challenge is asking the right questions and of course knowing what you are doing, especially if you want to optimize your prediction accuracy.

In this blog I'm exploring an example of machine learning. The random forest algorithm. I'll provide an example on how you can use this algorithm to do predictions. In order to implement a random forest, I'm using R with the randomForest library and I'm using the iris dataset which is provided by the R installation.

Monday, March 20, 2017

Oracle SOA Suite: Find that composite instance!

When executing BPM or BPEL processes, they are usually executed in the context of a specific entity. Sometimes you want to find instances involved with a specific entity. There are different ways to make this easy. You can for example use composite instance titles or sensors and set them to a unique identifier for your entity. If they have not been used, you can check the audit trail. However, manually checking the audit trail, especially if there are many instances, can be cumbersome. Also if different teams use different standards or standards have evolved over time, there might not be a single way to look for your entity identifier in composite instances. You want to automate this.

It is of course possible to write Java or WLST code and use the API to gather all relevant information. It would however require fetching large amounts of data from the SOAINFRA database to analyse. Fetching all that data into WLST or Java and combining it, would not be fast. I've created a database package / query which performs this feat directly on the 11g SOAINFRA database (and most likely with little alteration on 12c).