I tried to mimic the R logo in jpg format from R site only with LaTeX in order to make it scalable with the context without external files.
This is the result at tiny, normal and huge size, compared with the jpg at scale 25%, 50 and 100%:

Evidently, the LaTeX logotype is far from perfect in many areas even at normal size, but the worst is that the proportion between character R and the background circles (\bircirc) is not constant, although everything is defined in em units. Why?
Could be a better way to construct a pretty inline R logo? Of course, it should be not the jpg file nor a scalable vector graphics (SVG) converted to pdf, nor a simple format of the R character, like \newcommand{\R}{\textbf{\textup{R}}}
This is the MWE code:
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{xspace}
\usepackage{xcolor}
\usepackage{graphicx}
\definecolor{Rcolor}{RGB}{150,160,190}
\newcommand{\R}{%
\raisebox{.3em}{\hspace{1.2em}%
\llap{\resizebox{1.09em}{.5em}{\color{black}$\bigcirc$}}%
\llap{\resizebox{1.199em}{.55em}{\color{darkgray}$\bigcirc$}}%
\llap{\resizebox{1.19em}{.52em}{\color{gray!50}$\bigcirc$}}%
\llap{\resizebox{1.1em}{.5em}{\color{gray}$\bigcirc$}}%
\llap{\resizebox{1.25em}{.55em}{\color{gray}$\bigcirc$}}%
}%
\hspace{-.85em}%
\textbf{%
%\resizebox{.55em}{1.5ex}{\textcolor{black!80}{\textsf{R}}}%
\textcolor{black}{\textsf{R}}%
\hspace{-.025em}\raisebox{.01em}{\llap{\textcolor{Rcolor}{\textsf{R}}}}%
}%
\xspace}
\begin{document}
Bitmap logo:
\includegraphics[scale=.25]{Rlogo.jpg}
\includegraphics[scale=.5]{Rlogo.jpg}
\includegraphics[scale=1]{Rlogo.jpg}
\LaTeX\ logo:~~
\tiny{\R} \normalsize{ \R} \Huge{\R}
\end{document}
