Integration of special Characters like Q̇ in R

Question

to label the axis in a ggplot2 in R with the derivative of Q, i need the character "Q with overdot" --> "Q̇"

is there a library or anything to integrate special characters like this?

Answer 1

I could not find a unicode code for Q̇, but you can use expression(dot(Q)), even though the dot may not be centered.

plot.new()
title(main = expression(dot(Q)))

Answer 2

There is no unicode character for Q-dot. An interesting read about that can be found here: http://www.personal.psu.edu/ejp10/blogs/gotunicode/2008/11/glyph-du-jour-thermodynamic-q-.html

Your rescue comes with the expressions, where you can place a single dot on anything. https://stat.ethz.ch/R-manual/R-devel/library/grDevices/html/plotmath.html

It will just place one . on top of the full string provided in the dot()

Some small example on the Stefan-Boltzmann Law

plot.new()
title(main = expression(dot(Q) == epsilon * sigma * A * (T[SURFACE]^4 - T[SURROUNDINGS]^4)))