# Style Guide

Sometimes, when there's no unique way to write something, you need to make a decision. Below are certain rules that I abide by. They are surely arbitrary to some degree, but at least I will stick to one way of doing something.

General rule: US English based on Merriam-Webster.

(Please don't take this as a snobby thing. It's literally just a reminder for myself.)

### Words I hyphen

• non-classical

• real-world problem

• line-source

• zeroth-order, first-order, second-order, ...

• left-hand side

• non-negative

• in-scattering

• pre-collision

### Words I don't hyphen

• path length distribution (not path lengths distribution)

• ray effects

• test case

• phase space

• cross section

• preprocess

### Referencing and citing

• From (1.1) and (1.2) follows ....

• I like Table 1.1.

• I like Figure 1.1.

• I like Algorithm 1.1.

• In Appendix A, ...

• There are many sections.

• I like Section A.

• This dates back to the original work by Doe .

• Ways to solve this problem are presented in [13,132,999].

• Previous work [9,2,3] used different approaches.

### Apostrophe

• The ball's position. (Ball is singular, apostrophe.)

• The balls' positions. (Balls is plural, no apostrophe.)

• Thomas's thesis. (No, your English teacher was wrong.)

• My Boss's ship. (Just to prove a point)

### Random things

• All chapter names have only the first letter capitalized.

• True, also for "List of figures", not "List of Figures".

• Ph.D. thesis, not PhD thesis

• Three things are important: (i) This, (ii) that, and (iii) something else.
(Use i), ii), ... for inline enumerations.)

• Bla bla, i.e., bla bla. (Two commas.)

• Bla bla, e.g., bla bla. (Two commas.)

• Bla bla et al.

• I want to thank you, you, and you. (Oxford comma.)

• Bla bla---something in between---bla bla. (Em-dash, no spaces around it.)

• spatial discretization

### Math things

• Small variables for n_x, n_y, n_q, ...

• Order is usually capitalized, i.e., order N

• time steps are usually the small n, f^n, f^{n+1}, ...

• i,j,k for spatial variables

• q for angular variable

• If it is an enumeration of equalities, use letter
a = 1 (1.2a)
b= 1 +0 (1.2b)
c= 1 + 2 -2 (1.2c)
or
1 = 1 (1.2a)
= 1 +0 (1.2b)
= 1 + 2 -2 (1.2c)

• Same for equivalence relations
1=1 (1.1a)
<=>2=2 (1.1b)

• Use commas this way
1=1
= 1+1,
and
a=1
<=>2a=2,
but
1=1,
2=2,
3=3.

• If you read it out, it makes sense.
First example: It follows 1 equal to 1 equal to 1+1, thus bla bla.
Second example: It follows a equal to 1 which is equivalent to 2a equal to 2. (This could be debatable though and is a bit motivated by convenience)
Third example: This is an enumeration: We know that 1 equal to 1, 2 equal to 2, and 3 equal to 3.

• Do not include a number for an equation that has already been mentioned and just gets recalled.

• Write non-bold letters for (multi-dimensional) subspaces, e.g. V \subset \mathbb{R}^3.