\begin{tikzpicture}[scale=0.6]
			%\draw [->] (0,-7.9) -- (0,7.9);
			%\draw [->] (-7.9,0) -- (7.9,0);
			%dots
			\foreach \x in {-4,...,4}
			\foreach \y in {-4,...,4}
			\draw[fill=black](\x,\y)circle(2pt);
			%++ region
			\foreach \x in {0,...,4}
			\foreach \y in {0,...,4}
			{\draw[->,>=latex,shorten >=2pt](\x,\y)--(\x+1,\y);
				\draw[->,>=latex,shorten >=2pt](\x,\y)--(\x,\y+1);}
			%-+ region
			\foreach \x in {0,...,4}
			\foreach \y in {\x,...,4}
			\draw[->,>=latex,shorten >=2pt](\x,-\y)--(\x,-\y-1);
			\foreach \x in {0,...,3}
			\foreach \y in {\x,...,3}
			\draw[->,>=latex,shorten >=2pt](\x,-\y-1)--(\x+1,-\y-1);
			%-- region
			\foreach \x in {0,...,3}
			\foreach \y in {0,...,\x}
			\draw[->,>=latex,shorten >=2pt](-\x-1,\y)--(-\x-1,\y+1);
			\foreach \x in {0,...,4}
			\foreach \y in {0,...,\x}
				\draw[->,>=latex,shorten >=2pt](-\x,\y)--(-\x-1,\y);
			\draw[fill=black](0,0)circle(4pt);
			\node[below left] at (0,0) {$\;(0,0)$};
\end{tikzpicture}