Math notations: percent sign in arXiv (via arXMLiv 2020)

Some quick statistics on the presence of the % character in a normalized plain-text version of the corpus:

7,055,855 matches
610,543 files contained matches
1,570,012 files searched

In other words 38% of arXiv appears to contain a use of the character, with an average of 11.5 uses per document, when used.

From a manual sample of ~200 articles, it appears % most often denotes "percentage", but that sample is not representative, and already has one exception (modulo). Also note that even in the cases with a "percentage" meaning, there are some grammatically interesting cases.

meaning	use	source
percentage over expression	$(0.5\pm 0.3)\mathrm{\%}$	arxiv:0904.3774
percentage over negative number	functions, at $-0.4\text{ to }-0.6\mathrm{\%}$	arxiv:0904.3998
percentage over range	account for $\sim 30-50\mathrm{\%}$ of the total mass	arxiv:0904.4784
range over percentages	$10\mathrm{\%}-13\mathrm{\%}$ uncertainty	arxiv:0904.1203
table cell datatype [unit]	${\mathcal{E}}_P[\mathrm{\%}]$ or $(\mathrm{\%})$ or $\delta /\mathrm{\%}$	arxiv:0904.4342 arxiv:hep-ph/0506110
percentage in chemical equation	${}^4\mathrm{He}+5\mathrm{\%}{\mathrm{C}}_4{\mathrm{H}}_{10}$	arxiv:0904.1667
atomic percentage	$\approx 4\text{ at. }\mathrm{\%}\text{ of }\mathrm{Mn}$	arxiv:0904.0297
percentage by weight	$wt\text{hyphen}\mathrm{\%}$ or $wt\mathrm{\%}$	arxiv:1307.2138
percentage as set element	$\{2\mathrm{\%},4\mathrm{\%}\}$	arxiv:1804.02749
modulo	${\mathit{Z}}_t=\{\begin{array}{ll}{\mathit{Z}}_a& \text{ if }t\mathrm{\%}2=0\\ {\mathit{Z}}_b& \text{ else }\end{array}$	arxiv:1804.11027

Aside: in programming

meaning	use	source
Mathematica alias for last result	%+1 or %n, or…	arxiv:1307.6925
modulo	x % 2
formatting spec	ratio=%f	arxiv:math/0506626
matlab comment	x_e = x ( ind_e ); %restriction - all	arxiv:1911.03973