Link to CV.
How long does it take to cross the start line at the Comrades Marathon? If you’re lucky enough to be starting in one of the batches which is close to the front then this might be a matter of seconds to a couple of minutes. But if you’re in a batch closer to the back then this could be anything up to ten or eleven minutes. This is an agonising wait when all you want to do is start running.
Read More →The Comrades Marathon is an epic ultramarathon run each year between Durban and Pietermaritzburg (South Africa).
A few years ago I put together a simple spreadsheet for generating a Comrades Marathon pacing strategy. But the spreadsheet was clunky to use and laborious to maintain. Plus I was frustrated by the crude plots (largely due to my limited spreadsheet proficiency). It seemed like an excellent opportunity to create a Shiny app.
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At Fathom Data we do a lot of automated reporting with R. Being able to easily and reliably send emails is a high priority.
There is already a selection of packages for sending email from R:
{mailR}{gmailr}{blastula}{blatr} (Windows){mail} and{sendmailR}.We’ve had the most experience with the first two, both of which are really solid packages. However, {gmailr} uses the Google Mail API so it doesn’t work with all SMTP servers and {mailR} has a dependency on {rJava} which can be a bit of a hurdle for deploying in some environments.
When I set up an R server for clients they often want to be able to install packages so that all users on the machine have access to them. This requires them to be able to install the packages onto the root filesystem rather that under their individual home directories.
It would be easy enough to give them su access, but this is a risky approach. There are so many other things on the system that they could break with this level of power.
I’m helping develop a new game concept, which is based on the sliding puzzle game. The idea is to randomise the initial configuration of the puzzle. However, I quickly discovered that half of the resulting configurations were not solvable. Not good! Here are two approaches to getting a solvable puzzle:
The first option is obviously more robust. It’s also a bit more work. The second option might require a few iterations, but it’s easy to implement.
Read More →Qlik Sense is a tool for exploratory data analysis and visualisation. It’s powerful and versatile. It’s can, however, be significantly enhanced by interfacing with R.
Read More →Arrived in Paris rather late after catching the Eurostar from London. Trip nearly started on a bad note when I underestimated the time required to check-in, get through passport control and security. Sat down on the train literally as it departed.
Early start, working on my tutorial for satRday. When the Sun came up I went out for a trot, primarily to get acquainted with the neighbourhood but also to locate the grave of Jim Morrison. Arrived at Père Lachaise Cemetery to find that it only opened at 08:00. Mildly disappointed. The breakfast that I had back at the hotel made up for that though.
Read More →I need to deploy a Plumber API in a Docker container. The API has some R package dependencies which need to be baked into the Docker image. A few options for the base image:
The first option, r-base, would require building the dependencies from source, a somewhat time consuming operation. The last option, r-apt, makes it possible to install most packages using apt, which is likely to be much quicker. I’ll immediately eliminate the other option, tidyverse, because although it already contains a load of packages, many of those are not required and, in addition, it incorporates RStudio Server, which is definitely not necessary for this project.
Rserve is a server which allows other programs to use the facilities of R via TCP/IP.
Starting with JSON body because this is the way that most API documentation will give you the payload examples.
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At one of my clients I run RStudio under Citrix in order to have access to their data.
For the most part this works fine. However, every time I visit them I spend the first few minutes of my day installing packages because my environment does not seem to be persisted from one session to the next.
I finally had a gap and decided to fix the problem.
Installed packages just spontaneously disappear… That’s weird. Where are they being installed?
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Analysing survey data can be tricky. There’s often a mismatch between the characteristics of the survey respondents and those of the general population. If the discrepancies are not accounted for then the survey results can (and generally will!) be misleading.
Read More →There’s a Debian package available for Citrix Receiver, so in principle this task should be trivial.
It’s not.
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One of the things I like most about web scraping is that almost every site comes with a new set of challenges.
I recently had to scrape a few product pages from the site of a large retailer. I discovered that these pages use an “accordion” to present the product attributes. Only a single panel of the accordion is visible at any one time. For example, you toggle the Details panel open to see the associated content.
Read More →I fairly often set up servers to host both Shiny and RStudio servers. This is my recipe.
Read More →I did a remote install of Ubuntu Server today. This was somewhat novel because it’s the first time that I have not had physical access to the machine I was installing on. The server install went very smoothly indeed.
The next tasks were to install RStudio Server and Shiny Server. The installation process for each of these is well documented on the RStudio web site:
These are my notes. Essentially the same, with some small variations.
Read More →There’s a magnificent variety of open data available on AWS. To see the full list, head over to the Registry of Open Data on AWS.
Read More →I use HTML to generate slide decks. Usually my HTML will reference a host of other files on my machine (CSS, JavaScript and images). If I want to distribute my deck then I have a couple of options:
Both of these have problems. In the former case the HTML just ends up looking like ass because it relies on all of those dependencies to sort out the aesthetics. In the latter case I need to take care of the directory structure and, if those dependencies are distributed across my file system (which they generally are!) then this can be a challenge.
Read More →For years it’s been simple to set up DNS on a Linux machine. Just add a couple of entries to /etc/resolv.conf and you’re done.
I’ve just returned from PyConZA (2018), held at the Birchwood Hotel in Boksburg North (Johannesburg) on 11-12 October. A great conference with a super selection of talks and great catering.
Obviously when the PyCon call for papers came out I was feeling ambitious because I submitted a Workshop and a Talk. They were both accepted, so that put the pressure on a bit.
I gave a full day pre-conference workshop on 10 October entitled “Introduction to Python for Data Science”. In retrospect it would have been a better idea to call it “Introduction to Data Science using Python”.
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