在 tikzset 中使用坐标

Question

我尝试将两个坐标传递给 tikzset 并在这些点之间绘制箭头。但是，它不起作用。我猜这是因为对坐标的解释。我的 MWE 结果是错误的；

\documentclass[border=5mm]{standalone}
\usepackage{tikz}

\tikzset{
  pics/somearrow/.style 2 args={
    code={
      %\coordinate (A) at {#1}; %%doesn't work either.
      %\coordinate (B) at {#2};
      %\draw [->] (A) -- (B);
      \draw [->] #1 -- #2;
    }}}

\begin{document}

  \begin{tikzpicture}
  \draw[help lines] (0,0) grid (5,5);

  \foreach \from/\to in
  { {(0,0)}/{(3,3)},
    {(2,5)}/{(4,2)},
    {(4,4)}/{(2,5)}  }
  { \pic at \from {somearrow={\from}{\to}}; }
  \end{tikzpicture}

\end{document}

（我对 tikz 还很陌生。）

Answer 1

请注意 的原点pic位于其插入点。因此 中的{ \pic at \from {somearrow={\from}{\to}}; }两个参数都相对于at \from。

要得到

你可以使用

\documentclass[border=5mm]{standalone}
\usepackage{tikz}

\tikzset{
  pics/somearrow/.style 2 args={
    code={
      \draw [->] #1 -- #2;
    }}}

\begin{document}

  \begin{tikzpicture}
  \draw[help lines] (0,0) grid (5,5);

  \foreach \from/\to in
  { {(0,0)}/{(3,3)},
    {(2,5)}/{(4,2)},
    {(4,4)}/{(2,5)}% the % is here important
  }
  { \pic at (0,0) {somearrow={\from}{\to}}; }
  \end{tikzpicture}

\end{document}

或者

\documentclass[border=5mm]{standalone}
\usepackage{tikz}

\tikzset{
  pics/somearrow/.style={
    code={
      \draw [->] (0,0) -- #1;
    }}}

\begin{document}

  \begin{tikzpicture}
  \draw[help lines] (0,0) grid (5,5);

  \foreach \from/\to in
  { {(0,0)}/{(3,3)},
    {(2,5)}/{(2,-3)},
    {(4,4)}/{(-2,1)}% the % is here important
  }
  { \pic at \from {somearrow=\to}; }
  \end{tikzpicture}

\end{document}