Two-Step fix for rJava library installation on Mac OS

-
I've been using R for some time and over the years I've had one consistent nagging problem. 

rJava

Perhaps the single most temperamental library in the whole history of R. If you are like me, you likely try to avoid anything Java based, like using openxlsx instead of xlsx. I don't use Java but a number of libraries I do use, have it as a dependency. For example, I like to use qdap because it has a lot of nice tools for qualitative analysis, which of course uses Java.

The big problem is that rJava never installs properly and gives some error along the lines of not being able to find jdk files, jni.h, or Java home when you try to call the library. I have a couple quick steps here that can get rJava up and running quickly. I haven't noticed this issue in Windows which means the library is probably written for Windows and the developer hasn't bothered to make it function out-of-the-box on Mac OS.

Two quick steps and you can get rJava working in R on Mac OS.
  1. Download the Java Developer Kit Java SE for Mac at this website.
    1. Click "JDK Download"
    2. On the new webpage, scroll down to the Mac OS installer.
    3. This installer should be signed by Oracle so you won't need to go into settings > 
      Security & Privacy to open the file.
  2. Set JAVA_HOME to the location of jni.h found in the new developer kit you just installed.
    1. Open the terminal. You can do this by clicking on the finder search icon at the top right of your desktop and entering "terminal"
    2. Once the terminal window is open, enter the following command. 
    3. R CMD javareconf JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-14.0.1.jdk/Contents/Home/include
      1. Check the Java SE version. If the version is not 14.0.1, you will need to update this to the current version you just downloaded and installed. If you didn't notice what the version was you can enter "java -version" in the terminal. It is also listed on the webpage I linked above.
    4. That command should run for a few seconds and finish with a "done".
With that done you should be ready to rock. Restart R or Rstudio and rJava ought to load just fine.

I hope this post helps people out there! It has been difficult for me to find solutions for this over the years, and because it is still a problem I figured I would write up a quick guide.

Comments

Post a Comment

Popular posts from this blog

How to Get Started Playing Super Metroid / Link to the Past Crossover Randomizer.

-
I've purchased and enjoyed classic consoles like the Super Nintendo Classic and replayed some of the beloved games from my childhood. After redoing a game once, I'm good for a while, and am left hoping for some way to make it more interesting once the nostalgia wears off. One way to make classic games more interesting was to watch speed runs. I've been a fan of watching speed running classic games, like Super Metroid, for some time now. Recently, I noticed many runners starting to participate in randomizer races and was immediately fascinated. The dynamic is different than typical speed-running which focuses on runners mastering mostly repetitive strategies and precise execution. Admittedly, that is still quite entertaining, however, randomizers add a new dimension where you have to think through game logic in order progress. It also adds an element where your regular Joe can play the game and enjoy a new twist every time without spending countless hours mastering particu
Read more

Mine Cryptocurrency with your Raspberry Pi!

-
Image
A year or so ago I got a Raspberry Pi for the purpose of building an emulation station, which works wonderfully. As time has gone on, I've wondered if there isn't more I could be doing with my Raspberry Pi as it is capable of much more than nostalgic gaming. At the same time, I've become more of a crypto enthusiast as the advent of blockchain technology continues to revolutionize the way people can improve and simplify financial transactions, among other aspects of the computing industry. My intention isn't to provide a plug for blockchain tech, rather describe a way to combine two interests. Before I get into how to get your raspberry pi to mine cryptocurrency, let's first be honest about the profitability of such an endeavor. Many mining algorithms are very complex and take a lot of computational power, not to mention, the cost of powering such a system. For this reason, people have to build mining farms to make such an endeavor profitable. Whereas, raspberry
Read more

Structural Machine Learning in R: Predicting Probabilistic Offender Profiles using FBI's NIBRS Data

-
Image
What is Structural Machine Learning? Most machine learning tasks are designed for classifying data, but what if you have multiple outcomes? Not only do you have multiple outcomes (Y's or output variables), but you also need to enforce specific relationships among those outcomes and your predictors (X). Traditional ML can do many things, but this is not one of them. Traditional ML classifiers have one outcome and they attempt to classify that univariate outcome. A genre of machine learning that handles multiple outcomes and allows data scientists to specify a structure among all variables of interest is called "structured prediction". This genre of ML has existed in the literature for many years, but isn't something I've come across much, so I figured I would present a simple form of structured prediction and motivate it with an illustrative example. The Problem I'll motivate this with the idea of criminal profiling. It's an interesting subject and somethin
Read more