mymacros.tex

\newcommand{\norm}[1]{\|#1\|}
\newcommand{\normtwo}[1]{\|#1\|_2}
\newcommand{\normtwolr}[1]{\left\|#1\right\|_2}
\newcommand{\normone}[1]{\|#1\|_1}
\newcommand{\norminf}[1]{\|#1\|_\infty}
\newcommand{\normfrob}[1]{\|#1\|_{\text{F}}}
\newcommand{\transp}{^{\mathrm{T}}}

\newcommand{\RR}{\mathbb R} % Real numbers
\newcommand{\CC}{\mathbb C} % Complex numbers
\newcommand{\Kry}{\mathcal{K}} % Krylov subspace
\newcommand{\OO}{\mathcal{O}} % Big-O
\newcommand{\PP}{\mathcal{P}} % polynomials of degree <= n
\newcommand{\rP}{\mathrm{P}} % polynomials with p(0)=1

\DeclareMathOperator{\Ker}{Ker} % Kernel
\DeclareMathOperator{\rank}{Rank}
\DeclareMathOperator{\range}{Range}
\DeclareMathOperator{\sspan}{Span}
\DeclareMathOperator{\trace}{trace}
\DeclareMathOperator{\diag}{diag}


\makeatletter
\newcommand{\hathat}[1]{% 
\begingroup%
  \let\macc@kerna\z@%
  \let\macc@kernb\z@%
  \let\macc@nucleus\@empty%
  \hat{\raisebox{.2ex}{\vphantom{\ensuremath{#1}}}\smash{\hat{#1}}}%
\endgroup%
}
\makeatother