یک روش دیگهای هم آقای احمدی لطف کردن که خیلی جالبه
کد:
% M.Ahmadi 990613
% @Tex_Ahmadi
\documentclass[12pt]{report}
\usepackage{amsmath,tikz}
\usetikzlibrary{decorations.pathmorphing,tikzmark}
\usepackage{xepersian}
\settextfont{Yas}
\begin{document}
\begin{equation}
M_r=\tikzmark{a}\qquad\qquad
\begin{array}{lcl}
\tikzmark{b}\text{دادههای طبقهبندی نشده}&\longrightarrow &
\frac{\sum\left(x_i-a\right)^r}{N}
\\
&&
\\
\tikzmark{c}\text{دادههای طبقهبندی شده}&\longrightarrow &
\frac{\sum F_i\left(x_i-a\right)^r}{N} =
\sum f_i\left(x_i-a\right)^r
\end{array}
\end{equation}
\begin{tikzpicture}[remember picture,overlay]
\draw[->,decorate, decoration={snake, pre length=0.5mm, post length=1mm, amplitude=0.4mm, segment length=2mm},blue] ([yshift=2mm,xshift=-1mm]pic cs:a) -- ([xshift=-0.5ex]pic cs:b);
\draw[->,decorate, decoration={snake,pre length=0.5mm,post length=1mm,amplitude=-0.4mm,segment length=2mm},blue] ([xshift=-1mm]pic cs:a) -- ([xshift=-0.5ex,yshift=.5mm]pic cs:c);
\end{tikzpicture}
%++++++++++++++++++++++
\begin{equation}
M_r=\tikzmark{a1}\qquad\qquad
\begin{array}{lcl}
\tikzmark{b1}\text{دادههای طبقهبندی نشده}&\longrightarrow &
\frac{\sum\left(x_i-a\right)^r}{N}
\\
&&
\\
\tikzmark{c1}\text{دادههای طبقهبندی شده}&\longrightarrow &
\frac{\sum F_i\left(x_i-a\right)^r}{N} =
\sum f_i\left(x_i-a\right)^r
\end{array}
\end{equation}
\begin{tikzpicture}[remember picture,overlay]
\draw[->,decorate, decoration={snake, pre length=0.5mm, post length=1mm, amplitude=0.4mm, segment length=2mm},red] ([yshift=1.6mm,xshift=-1mm]pic cs:a1) -- ([xshift=-0.5ex]pic cs:b1);
\draw[->,decorate, decoration={snake,pre length=0.5mm,post length=1mm,amplitude=-0.4mm,segment length=2mm},red] ([yshift=.6mm,xshift=-1mm]pic cs:a1) -- ([xshift=-0.5ex,yshift=.5mm]pic cs:c1);
\end{tikzpicture}
\end{document}
خروجی: