# Cerebral Mastication

## 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:

## Teens and the Internet...

Given that I have a small version of myself running around my house, I think about how she’ll use the Internet when she gets older. Just the other day she, “Asked Google something” which made me realize that, although she’s just barely literate, my kid is going to “be online” for the rest of her life. Although I’m not really sure what “be online” will mean for her over the years.

## Installing & Debugging ODBC on Mac OS X

[](https://www.cerebralmastication.com/wp-content/uploads/2013/01/Screenshot_1_31_13_10_06_AM1.png)I just spent nearly two full days in a bare knuckle brawl with my Macbook Pro trying to get it to talk to a corporate MS SQL Server. I had abandoned MSSQL more than a year ago in favor of PostgreSQL because of how much easier it is to work with PostgreSQL from a non-Microsoft stack. At that point I was R running on Linux and soon R running on OS X.

## Solving easy problems the hard way

There’s a charming little brain teaser that’s going around the Interwebs. It’s got various forms, but they all look something like this: This problem can be solved by pre-school children in 5-10 minutes, by programer – in 1 hour, by people with higher education … well, check it yourself! ![:)](http://girlsaregeeks.com/WPApp/wp-includes/images/smilies/icon_smile.gif) 8809=6 7111=0 2172=0 6666=4 1111=0 3213=0 7662=2 9313=1 0000=4 2222=0 3333=0 5555=0 8193=3 8096=5 7777=0 9999=4 7756=1 6855=3 9881=5 5531=0 2581=?

## Fitting Distribution X to Data From Distribution Y

I had someone ask me about fitting a beta distribution to data drawn from a gamma distribution and how well the distribution would fit. I’m not a “closed form” kinda guy. I’m more of a “numerical simulation” type of fellow. So I whipped up a little R code to illustrate the process then we changed the parameters of the gamma distribution to see how it impacted fit. An exercise like this is what I call building a “toy model” and I think this is invaluable as a method for building intuition and a visceral understanding of data.