knitr
out.width
fig.width
render_book()
serve_book()
toc_depth
fig.cap
fig.pos="H"
axis description cs
declare function
pgfmathparse
pgfmathdeclarefunction
|-
-|
pgfplotsinvokeforeach
addplot+
%>%
dplyr
ggplot2
%/%
rep
seq
<<-
tableone
lifelines
%r
https://www.zhihu.com/question/27068465/answer/3318941468