The key package is mathtools.pdf
\usepackage{amsmath}
\usepackage{mathtools}
\usepackage{etoolbox}
\DeclarePairedDelimiterX\norm[1]\lVert\rVert{\ifblank{#1}{\,\cdot\,}{#1}}
\DeclarePairedDelimiterX\abs[1]{\lvert}{\rvert}{\ifblank{#1}{\,\cdot\,}{#1}}
\DeclarePairedDelimiterX\innerp[2]{\langle}{\rangle}{\ifblank{#1#2}{\,\cdot\,,\cdot\,}{#1,#2}}
\newcommand{\sharm}[3][]{\ifblank{#1}{Y^{#2}_{#3}}{\prescript{}{#1}Y^{#2}_{#3}}}
\[
\sharm[s]{m}{\ell} \quad \sharm{m}{\ell}
\]
[06 Sep 2016]
—
Latex labels with MATLAB®[21 Jul 2015]
—
TikZ–tikzexternalize to png[18 Jul 2015]
— Spherical Harmonics LaTeX Macros [01 Aug 2015]
—
BibDesk Publication html Export[06 Aug 2015]
—
Spherical Harmonic Plotting with MATLAB®[18 Jul 2015]
— Spherical Harmonics LaTeX Macros [16 Jul 2015]
—
Spherical Harmonic MATLAB® Code 1[06 Aug 2017]
—
HLab–1[31 Jul 2015]
—
Outputing png from pgfornament[18 Jul 2015]
—
Improving Gauss-Legendre