我怎样才能将向下的箭头放在“M 估计”的中间？

Question

我怎样才能将向下的箭头放在“M 估计”的中间？我尝试使用 \centering，但没有用

\documentclass[10pt]{beamer}
\usetikzlibrary{shapes,arrows}

\tikzset{
    myarrow/.style={
        draw,
        fill=red,
        single arrow,
        minimum height=2.5ex,
        line width=1pt,
        single arrow head extend=0.1ex
    }
}
\newcommand{\arrowdown}{%
\tikz [baseline=-1ex]{\node [myarrow,rotate=-90,  yscale=.5, single arrow head extend=1mm] {};}
}
\newcommand{\arrowright}{%
\tikz [baseline=-1ex]{\node [myarrow,rotate=0,  yscale=.5, single arrow head extend=1mm] {};}
}
    \begin{frame}
     \frametitle{The Kelly Passive approaches}       

\begin{columns}[t]
\begin{column}{0.6 \textwidth}
\begin{itemize}
\item \textit{M}-estimation\\
 \arrowdown\\
\end{itemize}

\end{column}
\begin{column}{0.5 \textwidth}
\begin{itemize}
\item  Kelly Jr, 1956\\
\small{Kelly portfolio};\\
\small{Geometric Mean maximisation portfolio strategy (GM-V)};\\

 \arrowdown\\
 \small{ $$\max\limits_{w_{t}} E_{t} \left[  log(w^{T}_{t}R_{t})\right]$$ such that $$w_{t} \geq0, \sum w_{t}=1$$}
\end{itemize}
\end{column}
\end{columns}



        \end{frame}   

Answer 1

这主要是为了使您的代码可编译，并建议您，如果您真的想创建这样的图表，您可以使用tabulars 将内容居中。不用说，还有更多优雅的方法来实现类似的图表。

\documentclass[10pt]{beamer}
\usepackage{array}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows}

\tikzset{
    myarrow/.style={
        draw,
        fill=red,
        single arrow,
        minimum height=2.5ex,
        line width=1pt,
        single arrow head extend=0.1ex
    }
}
\newcommand{\arrowdown}{%
\tikz [baseline=-1ex]{\node [myarrow,rotate=-90,  yscale=.5, single arrow head extend=1mm] {};}
}
\newcommand{\arrowright}{%
\tikz [baseline=-1ex]{\node [myarrow,rotate=0,  yscale=.5, single arrow head extend=1mm] {};}
}
\begin{document}
\begin{frame}[t]
\frametitle{The Kelly Passive approaches}       

\begin{columns}[t]
\begin{column}{0.48\textwidth}
 \begin{tabular}{>{\centering\arraybackslash}p{0.9\linewidth}}
\textit{M}-estimation\\
 \arrowdown\\[2.3cm]
 \end{tabular}
\end{column}
\begin{column}[t]{0.48\textwidth}
 \begin{tabular}{>{\centering\arraybackslash}p{0.9\linewidth}}
Kelly Jr, 1956\\
\small{Kelly portfolio};\\
\small{Geometric Mean maximisation portfolio strategy (GM-V)};\\
 \arrowdown\\
 \small{ $\max\limits_{w_{t}} E_{t} \left[  log(w^{T}_{t}R_{t})\right]$
  such that $w_{t} \geq0, \sum w_{t}=1$}
\end{tabular}  

\end{column}
\end{columns}
\end{frame}   
\end{document}