A word on notation

When possible, I’ve tried to be consistent with my notation on this blog.

For math

I use MathJax to render variables ($x$, $y$, $z$, etc.), mathematical functions ($f$, $g$, $h$, etc.), and mathematical objects ($\mathbf{R}^n$, etc.). I adopt single letters for variables and function names and use boldface for typical domains, $\mathbf{R}^n$, $\mathbf{Z}^n$, and $\mathbf{C}^n$.

I do not use italics or arrows to distinguish vectors from scalars: these I (should) make clear by the inclusion in the proper set. For instance, a three element vector $x$ would be introduced as: $x \in \mathbf{R}^3$.

Finally, I use uppercase letters to denote matrices, $A$, $B$, $C$, etc.

For code

When referring to a binary application, such as redis-client, I use Markdown with backticks. I also use backticks to refer to a method, function, or variable in the code. For instance, I might reference foobar from the following snippet.

def foobar():
    print("hello")

For code literals, I will also use backticks, 3, "abc", etc.

I also use backticks to refer to paths on a filesystem, such as /home/foobar, and I use shell variable expansion $YOUR_API_KEY to refer to user-dependent environment variables.

Finally, I use long variable names for naming functions, classes, modules, etc. I do this even when naming variables corresponding to mathematical objects:

def matrix_multiply(matrix_A, vector_x):
    return matrix_A @ vector_x

On functions

I try not to conflate a function in math with a function in code. These are subtly different in that a function in code can have side effects and causes it to behave differently from the usual function in math.

Certain languages (the functional kind) try to close this gap, but most do not. I find it useful to keep this distinction in mind when writing about both math and code.