绘制两个半连通的圆形网格

Question

我正在尝试从 neuronetworksanddeeplearning.com (第 6 章)复制下面的图像：

我得到了网格（虽然第二个没有居中）但我不知道如何在网格上方添加线条/箭头和标题。

我的代码：

\documentclass[11pt]{article}

\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usepackage{xifthen}

\begin{document}

\begin{tikzpicture}
  \foreach \x in {0,...,27}
    \foreach \y in {0,...,27} {
        \ifthenelse{\x < 5 \AND \y > 22}{\draw[black] (0.2*\x, 0.2*\y) circle (0.05cm);}{\draw[gray] (0.2*\x, 0.2*\y) circle (0.05cm);}
    }

  \foreach \x in {0,...,23}
    \foreach \y in {0,...,23} {
        \ifthenelse{\x < 1 \AND \y > 22}{\draw[black] (8 + 0.2*\x, 0.2*\y) circle (0.05cm);}{\draw[gray] (8 + 0.2*\x, 0.2*\y) circle (0.05cm);}
    }
\end{tikzpicture}

\end{document}

Answer 1

如果使用\nodes 而不是命令，则可以方便地根据和\draw的值标记每个圆圈。然后，您可以使用这些标签来绘制线条和放置标题：\x\y

\documentclass[11pt]{article}

\usepackage{tikz}
\usepackage{xifthen}

\begin{document}

\begin{tikzpicture}[inner sep=0.5mm]
  \foreach \x in {0,...,27}
    \foreach \y in {0,...,27} {
        \ifthenelse{\x < 5 \AND \y > 22}
        {\node[circle,draw=black] (A-\x-\y) at (0.2*\x, 0.2*\y) {};}
        {\node[circle,draw=gray] (A-\x-\y) at (0.2*\x, 0.2*\y) {};}
    }

  \foreach \x in {0,...,23}
    \foreach \y in {0,...,23} {
        \ifthenelse{\x < 1 \AND \y > 22}
        {\node[circle,draw=black] (B-\x-\y) at (8 + 0.2*\x, 0.4 + 0.2*\y) {};}
        {\node[circle,draw=gray] (B-\x-\y) at (8 + 0.2*\x, 0.4 + 0.2*\y) {};}
    }
    \draw[->] (A-0-27) -- (B-0-23);
    \draw[->] (A-0-26) -- (B-0-23);
    \draw[->] (A-0-25) -- (B-0-23);
    \draw[->] (A-0-24) -- (B-0-23);
    \draw[->] (A-0-23) -- (B-0-23);
    \node[above=6pt] at (A-14-27) {input neurons};
    \node[above=6pt] at (B-11-23) {first hidden layer};
\end{tikzpicture}

\end{document}