\medskip
\begin{tikzpicture}
                         %%%%%%%%%%%%%%%%%%%%%%%%%%%%%
                         % Comment or uncomment crop %
                         %%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \clip[use as bounding box]
  %\draw[thick, black]
  (2,3) rectangle (10,8);
  \foreach \i in {0,1,...,20} {
    \foreach \j in {0,1,..., 10} {
      \draw[fill=black] (.2*\j + .5*\i, \j + .1*\i) circle (1pt) coordinate (v-\i-\j);
    }
  }
  \draw[very thick, green!80!black, ->] (v-9-4) -- (v-8-4);
  \draw[very thick, green!80!black, ->] (v-9-4) -- (v-9-5);
  \draw[very thick, red!80!black, ->] (v-9-4)   -- (v-19-2);
  \draw[very thick, red!80!black, ->] (v-9-4)   -- (v-18-2);
  \foreach \i in {0,1,...,10} {
    \draw[dotted, color=black!70] (v-0-\i) -- (v-20-\i);
  }
  \foreach \i in {0,1,...,20} {
    \draw[dotted, color=black!70] (v-\i-0) -- (v-\i-10);
  }
\end{tikzpicture}
\medskip
