### Learn Some Shell Script: For-loops

A lot of people I know seem to glory in their ignorance of the terminal. Which would be fine if they didn’t use it every day. Yes, bash is ugly. On the other hand, like many ugly things, it can be used as a brute tool to do a lot of mundane tasks.

### Why Live?

There was a footpath leading across fields to New Southgate, and I used to go there alone to watch the sunset and contemplate suicide. I did not, however, commit suicide, because I wished to know more of mathematics.

## Why The Second Derivative Test Works In One Dimension

### How To Make Alt Key Not Type Unicode On Macos

I actually prefer the term macOS to OSX.

## Prerequisites (In Order Of Importance)

### How to Get Rid of the Tildes in Vim 8 and Neovim

If your buffer has empty lines, they are filled with annoying tildes. Vim 8 and Neovim finally fix this by allowing you to conceal them with the following command:

### Mnenomic for Law of Total Variance

I have (what I find) a handy mnemonic for the law of total variance. It’s also sometimes called the conditional variance formula, or (the reason for this mnenomic) Eve’s law. At least if I’m quoting Wikipedia right.

### Notation for Stochastic Functions

I forget where I’ve seen this, but I like using a squiggly arrow to represent a function that returns a probability.

## (n,) vs. (n, 1)

### Importance Sampling, Trivialized

Algebraic manipulation is always a fun way to make something profound seem like mere trickery.

### I No Longer Like Python's Boolean Comparisons

1 or 2 # returns 1, not True
(1 or 1) == True # returns False


### Fixing Annoying Issue With Matplotlib Pyplot In macOS

Running plt.show() causes all sorts of issues on macOS. To fix them, switch your matplotlib backend to something besides MacOSX. I used Qt5Agg.

### Some Things Don't Change

From I Want to be a Mathematician, Paul Halmos’s autobiography.

### Deep Learning Book Chapter 11 Notes

Understanding the fundamentals in chapter 5, especially over and underfitting, really pays off. This chapter is really easy to read if you can even half-remember those earlier sections.