addons.sty

\usepackage[mathscr]{euscript}

%\definecolor{lightgray}{RGB}{190,190,190}

\newenvironment{note}[1]{
\vspace*{1em}\hrule\vspace*{1em}	
	{\color{lightgray} $\blacksquare$} \textbf{#1} \quad
}{
\vspace*{.75em}\hrule\vspace*{1em}
}
\newcommand{\br}{\\[1em]}

\renewcommand{\d}[0]{\,\mathrm{d}}

% Declare new PGF functions
\pgfmathdeclarefunction{gauss}{2}{%
  \pgfmathparse{1/(#2*sqrt(2*pi))*exp(-((x-#1)^2)/(2*#2^2))}%
}
\usepackage{xifthen}
\newcommand{\vecrow}[1][x]{
	#1_{1},#1_{2},\ldots,#1_{n}
}
\newcommand{\svecrow}[1][x]{
	#1_{1},\ldots,#1_{n}
}

\newcommand{\sumi}[1][i]{\sum_{#1=1}^\infty}
\newcommand{\brs}[1]{\left\{#1\right\}}
\renewcommand{\vec}[1]{\boldsymbol{#1}}

% Center all figures
\let\oldfigure\figure
\def\figure{\oldfigure[H]\centering}

\newcommand{\mean}[1]{\ensuremath{\,\mathrm{E}\left[#1\right]}}
\newcommand{\var}[1]{\ensuremath{\,\mathrm{VAR}\left[#1\right]}}

\renewcommand{\t}[0]{\ensuremath{^{\mathrm{T}}}}
\newcommand{\tab}{\hspace*{2em}}