Michael, a data scientist, who is working for a German railway and logistics company, recently told me during an FATUG Meetup that he loves Tableau’s R and Pyhton integration. As he continued, he raised the raised the question for using functions they have written in Julia. Julia, a high-level dynamic programming language for high-performance numerical analysis, is an integral part of newly developed data strategy in the Michael’s organization.
Tableau, however, does not come with native support for Julia. I didn’t want to keep Michael’s team down and was looking for an alternative way to integrate Julia with Tableau.
This solution is working flawless in a production environment since several months. In this tutorial I’m going to walk you through the installation and connecting Tableau with R and Julia. I will also give you an example of calling a Julia statement from Tableau to calculate the sphere volume.
1. Install Julia and add PATH variable
2. Install R, XRJulia and RServe
You can download base R from r-project.org. Next, invoke R from the terminal to install the XRJulia and the RServe packages:
3. Load libraries and start RServe
After packages are successfully installed, we load them and run RServe:
Make sure to repeat this step everytime you restart your R session.
4. Connecting Tableau to RServe
Now let’s open the Help menu in Tableau Desktop and choose Settings and Performance >Manage External Service connection to open the External Service Connection dialog box:
Enter a server name using a domain or an IP address and specify a port. Port 6311 is the default port used by Rserve. Take a look on my R tutorial to learn more about Tableau’s R integration.
5. Adding Julia code to a Calculated Field
You can invoke Calculated Field functions called SCRIPT_STR, SCRIPT_REAL, SCRIPT_BOOL, and SCRIPT_INT to embed your Julia code in Tableau, such as this simple snippet that calculates sphere volume:
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|if (!exists("ev")) ev <- RJulia()|
|y <- juliaEval("|
|4 / 3 * %s * ' + STR([Factor]) + ' * pi ^ 3|
6. Use Calculated Field in Tableau
You can now use your Julia calculation as an alternate Calculated Field in your Tableau worksheet:
Feel free to download the Tableau Packaged Workbook (twbx) here.
Further reading: Mastering Julia
— Alexander Loth (@xlth) October 11, 2017