13

I would like to use the Laplace transform symbol that appears in unicode (SCRIPT CAPITAL L U+2112)

Laplace Unicode

However, I could only find the following two symbols can be used for Laplace transforms:

mathcal and mathscr

There are other symbols provided by the math-unicode, but it seems that it does not work with pdflatex.

Any suggestions if a unicode-like symbol is available?

jak123
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2 Answers2

12

You can use the rsfso package:

\documentclass{article}
\usepackage[scr]{rsfso}

\newcommand{\Laplace}{\mathscr{L}}

\begin{document}

\begin{equation}
\Laplace\{\sin(t)\} = \frac{1}{s^2 + 1}
\end{equation}

\end{document}

enter image description here

Variant preamble if you need also mathrsfs (but in that case I'd simply use the script L provided by \mathscr{L}):

\usepackage{mathrsfs}
\let\RSFSmathscr\mathscr  % save the meaning of \mathscr
\usepackage[scr]{rsfso}
\let\RSFSOmathscr\mathscr % save the new meaning of \mathscr
\let\mathscr\RSFSmathscr  % restore the previous meaning

\newcommand{\Laplace}{\RSFSOmathscr{L}}
egreg
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  • For some reason this did not work for me. Maybe package conflicts. – jak123 Apr 22 '15 at 08:23
  • @jak123 Are you loading mathrsfs or similar? – egreg Apr 22 '15 at 08:46
  • Yes I'm loading mathrsfs. – jak123 Apr 22 '15 at 08:57
  • @jak123 Added. But you shouldn't use two different script alphabets. – egreg Apr 22 '15 at 09:19
  • There seems to be another problem. When I used your MWE's, I'm getting: PK font rrsfso10 could not be created. BTW, why is the @egreg tagging not working with me? – jak123 Apr 22 '15 at 10:57
  • @jak123 Update your TeX distribution. The tagging isn't needed for reaching the message owner, so the system removes it automatically. – egreg Apr 22 '15 at 11:01
  • I'm using MikTeX 2.9 (updated today), still not working. I'm giving up and reverting back to @steven-b-segletes solution. Thanks for your help anyway. I still appreciate any thoughts on how to fix this. – jak123 Apr 22 '15 at 11:54
11

Here, I use Bruno's \slantbox from Shear transform a "box" in conjunction with \mathscr.

EDITED to use John K's variant of \slantbox at Adjust custom made upright greek letters when used in subscripts in order to achieve better horizontal positioning within the \slantbox.

\documentclass{article}
\usepackage{mathrsfs}
\newsavebox\foobox
\newlength{\foodim}
\newcommand{\slantbox}[2][0]{\mbox{%
        \sbox{\foobox}{#2}%
        \foodim=#1\wd\foobox
        \hskip \wd\foobox
        \hskip -0.5\foodim
        \pdfsave
        \pdfsetmatrix{1 0 #1 1}%
        \llap{\usebox{\foobox}}%
        \pdfrestore
        \hskip 0.5\foodim
}}
\def\Laplace{\slantbox[-.45]{$\mathscr{L}$}}
\begin{document}
\begin{equation}
\Laplace\{\sin(t)\} = \frac{1}{s^2 + 1}
\end{equation}
\end{document} 

enter image description here

If one needs it to be able to scale down to \scriptscriptstyle, then this approach will work.

\documentclass{article}
\usepackage{mathrsfs,scalerel}
\newsavebox\foobox
\newlength{\foodim}
\newcommand{\slantbox}[2][0]{\mbox{%
        \sbox{\foobox}{#2}%
        \foodim=#1\wd\foobox
        \hskip \wd\foobox
        \hskip -0.5\foodim
        \pdfsave
        \pdfsetmatrix{1 0 #1 1}%
        \llap{\usebox{\foobox}}%
        \pdfrestore
        \hskip 0.5\foodim
}}
\def\Laplace{\ThisStyle{\slantbox[-.45]{$\SavedStyle\mathscr{L}$}}}
\begin{document}
\begin{equation}
\Laplace\{\sin(t)\} = \frac{1}{s^2 + 1} \quad\scriptscriptstyle
\Laplace\{\sin(t)\} = \frac{1}{s^2 + 1}
\end{equation}
\end{document} 

enter image description here