# Cerebral Mastication

## Using Python sympy in a Python code chunk in RMarkdown

I was recently asked about using sympy in Python to print $$LaTeX$$ formulas in RMarkdown notebooks. I misunderstood the question at first but after some thought I realized that I didn’t know if it would work… but I should try it. Yes, printing elements of a matrix. So it's due to the prog languages' differences ( R vs Python), not rmarkdown vs Jupyter Notebook? pic.twitter.com/Any4qIDHS7 — Eyayaw T. Beze (@EyayawBeze) July 25, 2020 I knew that I could run Python chunks in an RMarkdown notebook.

## Starting A Digital Ocean Instance From Docker Machine

My buddy Dusty recently asked me how to set up a Digital Ocean cloud instance for RStudio using a Docker image. Below is the information he needed, but captured here for future travelers. Most people who are considering using Docker understand that Docker allows setting up something akin to a virtual machine on their local computer. What’s less widely appreciated among non dev-ops folks is that Docker comes with a tool called docker-machine that allows setting up a Docker virtual system on a remote server.

## Publishing Bookdown to Netlify (automagically)

I didn’t realize this until today, but Netlify isn’t just a great place to host Hugo based blogs (like this one), but it’s also a great place to host Bookdown based book content. Like many R Bloggers, I like to use Blogdown to publish blog posts. But as Paul Teetor and I got near completion of R Cookbook 2nd Edition, I began to give some thought to where I would host the online version of the book.

## Dataiku Meetup 2019-01-23

Tonight I’m presenting at the Dataiku Analytics and Data Science Meetup. My presentation is an adaptation of what I presented at RStudio::conf(2019) but with an emphasis towards a non-R audience. The slides are here. I have about 5-10 min more time at Dataiku than I had at RStudio::conf so I added a few slides showing off R Markdown and data exchange between R and Python. I thought those might be interesting and new to a non-R focused audience.

## My Favorite Kathy Sierra Plot

One of my favorite graphs of all time is this one from Kathy Sierra: Figure 1: Kick Ass Threshold I used that in my RStudio::conf(2019) presentation in Austin last week. I’m working on a related prez and I decided to create my own version of Kathy’s chart using R. I played around with some simulations and found that the cumulative t and normal distributions gave good curves if I fiddled with their parameters.

## Slides from rstudio::conf 2019

I had amazingly positive feedback from my presentation on “Empathy in Action” today at rstudio::conf in Austin. My main focus was emphasizing that most business users don’t want to learn to code. They just want to kick ass. And coding can be a means to that end. While I’d like to think the response was because of my fantastic choice of GIFs illustrating what analysts do for a living:

## Missing Unicode Greek Characters in Bookdown LaTeX

I spent this morning fighting with Bookdown. I was going through reviewer notes for the R Cookbook 2nd Edition and my coauthor, Paul Teetor, had noted that some of the greek symbols we were using were not showing up in the text when the book was rendered to PDF. Oddly, it looked fine in HTML. This turned out to be a font issue. I was using XeLeTeX as my $$\LaTeX$$ engine specifically because it handles UTF-8 unicode well.

## Seed Picking - Like P Hacking only More Random

I’m working with Paul Teetor and O’Reilly Media to complete the 2nd Edition of the R Cookbook. We’re in the editing phase so we’re cutting things left and right. This seed picking example is one of the things that got cut. But I found it amusing so thought I would share it here. –JD Recently I was trying to illustrate random number generation and confidence intervals. In particular, I wanted to show that sometimes by chance our confidence bands don’t contain the true value of a parameter.

## Level Up from cron to Airflow with R on your Macbook

I recently wanted to run Apache Airflow on my laptop as an upgrade to cron. I don’t really want all the full power and fury that Airflow brings, but I’m not one to shy away from killing a gnat with a sledge hammer. I use conda to manage environments on my mac and I wanted to keep airflow in a conda environment. So I ran the following which sets up a conda environment called airflow then installs airflow in that environment.

## Named Excel Tables: A very good idea

Excel has this construct they call and “Excel Table” which is about as helpful as a bicycle maker naming their bike model, “Mountain Bike.” But the Excel folks named these things “Excel Table” so in order to prevent confusion (as if) I try to always capitalize the T in “Table” to make it clear we’re talking about a specific thing, not just any table of data in Excel. Excel Tables are the things we get when we click on “Format as Table” in Excel: