During the summer I was contacted by a hedge fund from Bahamas. The fund was looking for someone with R language skills on-site and insisted for phone interview. Besides obvious questions about finance, statistics, coding and how many tennis balls can fit in Boeing 747 (ok, this question was omitted), they ... [Read more...]

To follow on from the earlier post on using R through Java, it is even easier to get jri up and running as a NetBeans module. Why is this useful? Well the platform that the NetBeans IDE is built on … Continue reading → [Read more...]

The R package rJava allows R to be accessed in Java programs. The part of the package that allows this is jri. The notes on the rJava site about getting jri to work didn’t help me much getting it to … Continue reading → [Read more...]

Programmers should definitely know how to use R. I don’t mean they should switch from their current language to R, but they should think of R as a handy tool during development.Again and again I find myself working with Java code like the following. td.linenos { background-color: #f0... [Read more...]

Today I played a bit with JRI as part of rJava, a Java-R-interface. Here you can learn how to setup for Debian/Ubuntu/akins. [Read more...]

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I just published Java based code to pull tick data from Interactive Brokers. There are thousands tools to get tick data from IB, but I had one feature in mind. You can get maximum 50 quotes per second from Interactive Brokers (its IB limitation for TWS API) . Imagine a situation, when ... [Read more...]

I had some troubles installing rJava on Ubuntu. The easiest solution I found was installing from the command line using: Then it worked without any problems. [Read more...]

It would be nice if there were an R package, along the lines of RMySQL, for MongoDB. For now there is not – so, how best to get data from a MongoDB database into R? One option is to retrieve JSON via the MongoDB REST interface and parse it using the ... [Read more...]

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Every year, I single out what I think are the Top Five open source projects. This year, there's only one hold-over from previous years, and it's likely that I'm just going to give it a Lifetime Achievement Award and pick five others next year. 5. NetBe... [Read more...]

The ant package has been released to CRAN yesterday. As discussed in previous posts in this blog (here and here), the ant R package provides an R-aware version of the ant build tool from the apache project. The package contains an R script that c... [Read more...]

I have updated the ant package I described yesterday in this blog to add several things Now the R code related to and tasks can either be given as the code attribute or as the text inside the task The R code has acces... [Read more...]

ant is an amazing build tool. I have been using ant for some time to build the java code that lives inside the src directories of my R packages, see this post for example. The drawbacks of this approach are : that it assumes ant is available on... [Read more...]

Assuming rJava is installed and works, it is possible to take advantage of its magic to get the path where java is installed: $ Rscript --default-packages="methods,rJava" -e ".jinit(); .jcall( 'java/lang/System', 'S', 'getProperty', 'java.home' )... [Read more...]

This is a post in the series Mixing R CMD build and ant. Previous posts have shown how to compile the java code that lives in the src directory of a package and how to document this code using javadoc. This post tackles the problem of unit testin... [Read more...]

As indicated in this thread, completion after the dollar operator can be customized by defining a custom names method. Here I am showing how to take advantage of this to display fields and methods of java references (jobjRef objects from the rJava ... [Read more...]

It’s been a long time since I posted here, for a number of reasons: Change of focus from Ruby programming to Linux capacity planning, especially in the realm of I/O subsystems. You’ll find more about that at http://linuxcapacityplanning.com... [Read more...]