线路与节点未正确对齐

Question

我的自定义绘制线不是指向节点而是指向其他地方，我不知道为什么以及如何修复它：

\documentclass{standalone}
\usepackage{tikz}

\tikzset{
    every label/.style={
        font=\scriptsize,
        inner sep=1pt
    }
}

\newcommand{\stencilptreg}[4][]{\node[circle,fill,draw,inner sep=1.5pt,label={below:#4},#1] at (#2) (#3) {}}
\newcommand{\stencilptstg}[4][]{\node[circle,fill,white,draw=black,inner sep=1.5pt,label={below:#4},#1] at (#2) (#3) {}}
\newcommand{\difflinefw}[2]{\draw [red,->,shorten <= 0.1cm, shorten >= 0.2cm] (#1) to[out=30,in=150] (#2)}
\newcommand{\difflinebw}[2]{\draw [red,->,shorten <= 0.1cm, shorten >= 0.2cm] (#1) to[out=150,in=30] (#2)}

\begin{document}
        \begin{tikzpicture}[x=2cm,y=2cm]

        % First point
        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        \pgfmathsetmacro\j{0}
        \draw [black!50,thin] (0,\j) -- (5,\j);
        \foreach \i in {0,1,...,5} {
            \stencilptreg{\i,\j}{\i,\j}{$\i$};
        }
        \foreach \i in {0.5,1.5,...,4.5} {
            \stencilptstg{\i,\j}{\i,\j}{$\i$};
        }
        \stencilptstg[blue]{.5, \j}{}{};
        \difflinefw{0,\j}{0.5,\j};
        \difflinebw{1,\j}{0.5,\j};

        % SECOND POINT
        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        \pgfmathsetmacro\j{1}   
        \draw [black!50,thin] (0,\j) -- (5,\j);
        \foreach \i in {0,1,...,5} {
            \stencilptreg{\i,\j}{\i,\j}{$\i$};
        }
        \foreach \i in {0.5,1.5,...,4.5} {
            \stencilptstg{\i,\j}{\i,\j}{$\i$};
        }   
        \stencilptreg[blue]{1, \j}{}{};
        \difflinefw{0.5,\j}{1,\j};
        \difflinebw{1.5,\j}{1,\j};    

        % Third POINT
        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        \pgfmathsetmacro\j{2}   
        \draw [black!50,thin] (0,\j) -- (5,\j);
        \foreach \i in {0,1,...,5} {
            \stencilptreg{\i,\j}{\i,\j}{$\i$};
        }
        \foreach \i in {0.5,1.5,...,4.5} {
            \stencilptstg{\i,\j}{\i,\j}{$\i$};
        }   
        \stencilptreg[blue]{1.5, \j}{}{};
        \difflinefw{1,\j}{1.5,\j};
        \difflinebw{2,\j}{1.5,\j};      
        \end{tikzpicture}
\end{document}

我还想使用数学来迭代 $j$，但我需要写类似这样的内容：

\foreach \j in {0,...,9} {

        ...

        \stencilptreg[blue]{\j/2, \j}{}{};
        \difflinefw{(\j+1)/2-.5,\j}{(\j+1)/2-.5,\j};
        \difflinebw{(\j+1)/2+.5,\j}{(\j+1)/2+.5,\j};        
 }

但我不知道如何进行数学运算。

添加图片以供参考

不需要但是想要，有没有办法将浮点数转换为分数？

Answer 1

问题是，当你执行 时，你给节点赋予了与坐标相同的名称\stencilptreg{\i,\j}{\i,\j}{$\i$};，如果你改用\stencilptreg{\i,\j}{\i-\j}{$\i$};，这种混乱就会消失。当然，如果节点名称包含 ，就会出现问题.。这里有一个解决所有这些问题的建议，并执行循环。

\documentclass[tikz,border=3.14mm]{standalone}

\tikzset{
    every label/.style={
        font=\scriptsize,
        inner sep=1pt
    }
}

\newcommand{\stencilptreg}[4][]{\node[circle,fill,draw,inner sep=1.5pt,label={below:#4},#1] at (#2) (#3) {}}
\newcommand{\stencilptstg}[4][]{\node[circle,fill,white,draw=black,inner sep=1.5pt,label={below:#4},#1] at (#2) (#3) {}}
\newcommand{\difflinefw}[2]{\draw [red,->,shorten <= 0.1cm, shorten >= 0.2cm] (#1) to[out=30,in=150] (#2)}
\newcommand{\difflinebw}[2]{\draw [red,->,shorten <= 0.1cm, shorten >= 0.2cm] (#1) to[out=150,in=30] (#2)}

\begin{document}
        \begin{tikzpicture}[x=2cm,y=2cm]
        \foreach \j [evaluate=\j as \k using {int(\j/2)},
        evaluate=\j as \l using {int((\j+2)/2)}] in {0,...,8}
        {\draw [black!50,thin] (0,\j) -- (5,\j);
        \foreach \i in {0,1,...,5} {
            \stencilptreg{\i,\j}{A-\i-\j}{$\i$};
        }
        \foreach \i in {1,3,...,9} {
            \pgfmathsetmacro{\m}{\i/2}
            \stencilptstg{\i/2,\j}{B-\i-\j}{$\m$};
        }
        \stencilptstg[blue]{{(\j+1)/2},\j}{target-\j}{};
        \ifodd\j
         \pgfmathtruncatemacro{\m}{\j+2}
         \difflinefw{B-\j-\j}{target-\j};
         \difflinebw{B-\m-\j}{target-\j};
        \else
         \difflinefw{A-\k-\j}{target-\j};
         \difflinebw{A-\l-\j}{target-\j};
        \fi}

        \end{tikzpicture}
\end{document}