12.9.2 Greatest hits from previous weeks

12.9.2.1 How to typeset subscript in usual text mode?
12.9.2.2 How to write a function (piecewise) with bracket outside?
12.9.2.3 Which dot character to use in which context?
12.9.2.4 How do you make numbered equations in latex?
12.9.2.5 Nice scientific pictures show off
12.9.2.6 When should I use \input vs. \include?
12.9.2.7 Package natbib Error: Bibliography not compatible with author-year citations
12.9.2.1 How to typeset subscript in usual text mode?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=1013

It's easy to make subscripts in math mode: $a_i$. 
How do I make a subscript outside math environment, likethis? 
[subscripts]
 
asked by P Shved https://tex.stackexchange.com/landing/r/digest?cta=user&id=280 Score of 331
answered by Stefan Kottwitz https://tex.stackexchange.com/landing/r/digest?cta=user&id=213 Score of 218
12.9.2.2 How to write a function (piecewise) with bracket outside?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=32140

How to write this Piecewise function using LaTeX? 
I tried 
$ 
\begin{array}{cc} 
\{ & 
\begin{array}{cc} 
0 & x\leq 0 \\ 
\frac{100-x}{100} & 0\leq x\leq 100 \\ 
0 & ... 
[math-mode] [equations] [brackets]
 
asked by GarouDan https://tex.stackexchange.com/landing/r/digest?cta=user&id=5314 Score of 220
answered by Ant https://tex.stackexchange.com/landing/r/digest?cta=user&id=6984 Score of 270
12.9.2.3 Which dot character to use in which context?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=19180

Wikipedia lists several dot characters in Unicode.  These are the ones that are ambiguous to me: 
interpunct, middle dot (A^\[CenterDot])   ·   ·   U+00B7   "midpoint (in typography)" 
dot ... 
[symbols] [best-practices] [punctuation] [unicode] [unicode-math]
 
asked by endolith https://tex.stackexchange.com/landing/r/digest?cta=user&id=5773 Score of 246
answered by Danie Els https://tex.stackexchange.com/landing/r/digest?cta=user&id=1683 Score of 161
12.9.2.4 How do you make numbered equations in latex?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=75764

I would like to put in a code that automatically assigns a number to the equations in my documents preferably aligned on the right hand side. 
How can I go about this? 
\documentclass[a4paper,11pt]{... 
[formatting] [equations] [amsmath]
 
asked by Magpie https://tex.stackexchange.com/landing/r/digest?cta=user&id=16635 Score of 72
12.9.2.5 Nice scientific pictures show off

https://tex.stackexchange.com/landing/r/digest?cta=question&id=158668

Task 
Show off your best scientific illustration ! 
The main purpose of this question is to share beautiful scientific pictures, preferably with an educational aspect. 
Content 
Your post must contain ... 
[diagrams] [3d] [technical-drawing] [fun] [big-list]
 
asked by Thomas https://tex.stackexchange.com/landing/r/digest?cta=user&id=42660 Score of 581
answered by Charles Staats https://tex.stackexchange.com/landing/r/digest?cta=user&id=484 Score of 350
12.9.2.6 When should I use \input vs. \include?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=246

There are two different commands to incorporate another file into the source of some document, \input and \include. When should I use one or the other? What are the differences between them? Are there ... 
[include] [input]
 
asked by Phil Miller https://tex.stackexchange.com/landing/r/digest?cta=user&id=60 Score of 1561
answered by Michael Mrozek https://tex.stackexchange.com/landing/r/digest?cta=user&id=29 Score of 1453
12.9.2.7 Package natbib Error: Bibliography not compatible with author-year citations

https://tex.stackexchange.com/landing/r/digest?cta=question&id=54480

I have a basic tex file and a bibliography which is exported from Mendeley 
However, when I want to cite in the author-year style, I get the error: 
Package natbib Error: Bibliography not compatible ... 
[bibtex] [errors] [natbib]
 
asked by grrrbytes https://tex.stackexchange.com/landing/r/digest?cta=user&id=13217 Score of 290
answered by Josh Porter https://tex.stackexchange.com/landing/r/digest?cta=user&id=15128 Score of 154