\documentclass[crop,border=3,tikz,convert={outext=.svg,command=\unexpanded{pdf2svg
    \infile\space\outfile}},multi=false]{standalone}
\usepackage{ifthen}
\usetikzlibrary{math,decorations.pathmorphing,patterns}

\begin{document}

\def\myt{4.78}
\def\mypi{3.141592653589793}

\newcommand{\wave}[4]{
  \def\myA{#1}
  \def\mya{#2}
  \def\myB{#3}
  \def\myb{#4}
  \draw[ultra thick,blue,smooth,domain=0:5,samples=50] plot
  function {\myA*exp(-\mya*(10-x-\myt)**2)+\myB*exp(-\myb*(x-\myt)**2)};

  \foreach \a in {0,0.2,...,5}{
    \tikzmath{\myy=
      \myA*exp(-\mya*(10-\a-\myt)^2)+\myB*exp(-\myb*(\a-\myt)^2);
    }
    \tikzmath{\myv=0.4*(
      \mya*(10-\a-\myt)* \myA*exp(-\mya*(10-\a-\myt)^2)+\myb*(\a-\myt)*\myB*exp(-\myb*(\a-\myt)^2));
    }
    \fill[red] (\a,\myy) circle (0.6mm);

    \pgfmathparse{\a==4?1:0}
    \ifthenelse{\lengthtest{\myv pt > 0.1 pt} \OR \lengthtest{\myv pt < -0.1 pt}}{
      \draw[thick,->,tips=proper] (\a,\myy) -++ (0,\myv);
    }{
      \draw[thick] (\a,\myy) -++ (0,\myv);
    }
  }
}

\begin{tikzpicture}[>=latex,scale=1]
  \fill[white] (-0.5,-5.3) rectangle (6,3.5);
  %\draw[thick,->] (0,-0.3) -- (0,2.8) node[above]{\Large $y$};
  %\draw[thick,->] (-0.1,0) -- (5.5,0) node[below]{\Large $x$};
  \foreach \a in {-0.5,0,...,2.5}{
    \draw[dotted] (0,\a) -- (5.5,\a);
  }
  \wave{1.5}{5}{1.5}{5}
  %\fill[white] (5,-2) rectangle (10,2);
  \begin{scope}[shift={(0,-2.8)}]
    %\draw[thick,->] (0,-1.7) -- (0,1.8) node[above]{\Large $y$};
    %\draw[thick,->] (-0.1,0) -- (5.5,0) node[below]{\Large $x$};
    \foreach \a in {-1.5,-1,...,1.5}{
      \draw[dotted] (0,\a) -- (5.5,\a);
    }
    \wave{-1.5}{5}{1.5}{5}
    %\fill[white] (5,-2) rectangle (10,2);
    \fill[pattern = north east lines] (5,-1) rectangle (5.3,1);
    \draw[ultra thick] (5,-1) -- (5,1);
  \end{scope}
\end{tikzpicture}
\end{document}