Script-r Symbol

Question

The near-ubiquitous undergraduate reference on electrodynamics, "Introduction to Electrodynamics" by David Griffiths make extensive use of a script-r symbol, defined to be \vector{\scriptr} \equiv \vector{r} - \vector{r}^{\prime} and looks like:

Although the question of how to produce such a symbol in LaTeX is quite a common one I am yet to find a satisfactory solution. The closest I've found is from the physymb package and uses the Calligra fonts:

Sadly, there is not a bold variant of this character and it is far more cursive than I would like. I am hence wondering if there are any better facsimiles.

Answer 1

If you are willing to use lualatex and unicode-math. At least you can get a free script font, XITS or Asana. They both have a script font and its bold version.

rsfs is a free script font. But there seems to be no bold version.

Any way the glyphs in XITS and Asana are not exactly what you want. But if you only want script fonts with bold version instead of exactly reproduce the look in that book, they should work.

\documentclass{article}
\usepackage{amsmath}
\usepackage{unicode-math}
\setmathfont{XITS Math}

\def\az{abcdefghijklmnopqrstuvwxyz}
\def\AZ{ABCDEFGHIJKLMNOPQRSTUVWXYZ}

\begin{document}
  \begin{gather*}
    \mathscr{\az} \\
    \mathscr{\AZ} \\
    \mathbfscr{\az} \\
    \mathbfscr{\AZ}
  \end{gather*}
\end{document}

Answer 2

I don't know if anyone is still looking for this, but I believe I have found the simplest solution. To produce the bold, script r, use the physymb package and the command (in math mode) \pmb{\scriptr}. It's italicized bold, but bold nonetheless.

Answer 3

In MathTime \mathbcal{\altr} gives:

But the font isn't free...

And, my opinion is, that alternative r on print, even in handwriting, doesn't read well.

Answer 4

There is a script r in Free Serif

but unfortunately it's not available as bold face. You can compile with XeLaTeX the following scriptr.tex file (Free Serif is included in TeX Live)

\documentclass{standalone}
\usepackage{fontspec}
\setmainfont{Free Serif}
\begin{document}
\char"1D4C7
\end{document}

so getting a scriptr.pdf file, and use

\newcommand{\scriptr}{\includegraphics{scriptr}}

in your document. Maybe some shift is needed.