TikZ：缩放图像但保持绝对距离

Question

有没有办法在 TikZ 中指定“绝对打印距离”，以便即使图像被缩放，某些距离仍保持完整并以指定的距离打印？例如

\begin{tikzpicture}
\coordinate (A) at (0,0);
\coordinate (B) at (4,0);
\draw (A)--node[below]{4}(B);
\node at ($(A)+(180:.3cm)$){A};
\node at ($(B)+(0:.3cm)$){B};
\end{tikzpicture}
\hskip5mm
\begin{tikzpicture}[scale=0.1]
\coordinate (A) at (0,0);
\coordinate (B) at (40,0);
\draw (A)--node[below]{40}(B);
\node at ($(A)+(180:.3cm)$){A};
\node at ($(B)+(0:.3cm)$){B};
\end{tikzpicture}

请注意“下方”保持不变，但节点文本的距离在缩放版本中较小。有没有办法指定“.3cm”，使其在打印输出时为 .3cm，而不受图像缩放的影响？TIA。

Answer 1

设置在与坐标或线条有指定距离的标签不受缩放的影响，因此请用 A 和 B 标记线条的末端，而不是将标签构建为单独的节点。

\documentclass[border=2pt,tikz]{standalone}
\usetikzlibrary{calc}
\begin{document}
\begin{tikzpicture}
\coordinate[label={left=0.3cm:A}] (A) at (0,0);
\coordinate[label={right=0.3cm:B}] (B) at (4,0);
\draw (A)--node[below]{4}(B);
\end{tikzpicture}
\begin{tikzpicture}[scale=0.1]
\coordinate[label={left=0.3cm:A}] (A) at (0,0);
\coordinate[label={right=0.3cm:B}] (B) at (40,0);
\draw (A)--node[below]{40}(B);
\end{tikzpicture}
\end{document}

TikZ 提供了多种放置标签的选项。请参阅TikZ 手册了解详情。下面，标签向上移动了3mm（除了水平距离之外）。

\documentclass[border=2pt,tikz]{standalone}
\usetikzlibrary{calc}
\begin{document}
\begin{tikzpicture}
\coordinate[label={[yshift=3mm]left=3mm:A}] (A) at (0,0);
\coordinate[label={[yshift=3mm]right=3mm:B}] (B) at (4,0);
\draw (A)--node[below]{4}(B);
\end{tikzpicture}
\begin{tikzpicture}[scale=0.1]
\coordinate[label={[yshift=3mm]left=3mm:A}] (A) at (0,0);
\coordinate[label={[yshift=3mm]right=3mm:B}] (B) at (40,0);
\draw (A)--node[below]{40}(B);
\end{tikzpicture}
\end{document}

Answer 2

另一种可能性：coordinate [xshift=..., yshift=...]不受缩放的影响。

\documentclass{article}
\usepackage{tikz}
\begin{document}
\pagenumbering{gobble}
\begin{tikzpicture}[scale=2]
  %\draw (0, 0) -- (1, 1) -- ++(1, 0);              % doesn't work
  %\draw (0, 0) -- (1, 1) -- ++([xshift=1cm] 0, 0); % doesn't work
  \draw (0, 0)
    -- (1, 1)
    coordinate [xshift=1cm] (tmp)
    -- (tmp);
\end{tikzpicture}
\end{document}

或者，anchor按照平常的方式使用。

\begin{tikzpicture}
\coordinate (A) at (0,0);
\coordinate (B) at (4,0);
\draw (A)--node[below]{4}(B);
\node [anchor=0, outer sep=0.2cm] at (A){A};
\node [anchor=180, outer sep=0.2cm] at (B){B};
\end{tikzpicture}
\hskip5mm
\begin{tikzpicture}[scale=0.1]
\coordinate (A) at (0,0);
\coordinate (B) at (40,0);
\draw (A)--node[below]{40}(B);
\node [anchor=0, outer sep=0.2cm] at (A){A};
\node [anchor=180, outer sep=0.2cm] at (B){B};
\end{tikzpicture}

并outer sep控制间距。