答案1
以下是一些(粗略的,可能不是最佳的)尝试:
\documentclass[tikz]{standalone}
\begin{document}
\begin{tikzpicture}
\sffamily\tiny
\fill (0,0) circle (.07) node [above right] {$\mathsf{T[n,j]}$};
\fill (-2,0) circle (.07) node [above right] {$\mathsf{T[n,j\!-\!1]}$};
\fill (2,0) circle (.07) node [above right] {$\mathsf{T[n,j\!+\!1]}$};
\fill (0,2) circle (.07) node [above right] {$\mathsf{T[n\!+\!1,j]}$};
\draw (-2,0) -- (0,0) -- (2,0) (0,2) -- (0,0);
\foreach \x in {-2,0,2}
\draw [thin,gray] (\x,-0.5) -- (\x,-0.45) (\x,2.5) -- (\x,2.45);
\foreach \x in {0,2}
\draw [thin,gray] (-3,\x) -- (-2.95,\x) (2.95,\x) -- (3,\x);
\draw (-3,-0.5) -- node [midway, above, sloped] {time} (-3,2.5) -- node [midway,above] {FTCS explicit scheme} (3,2.5) -- (3,-0.5) -- cycle node [midway,below] {space};
\end{tikzpicture}
\end{document}
如果有任何不清楚的地方,请随时在评论中询问。