使用节点锚点制作平行线

Question

T_C如何使用和T_zero锚点使红线与上面的两条线平行？

\documentclass[12pt]{article}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,shapes,positioning,intersections,quotes,patterns,patterns.meta,shapes.misc,shapes.geometric,calc}
\definecolor{viola}{HTML}{8100FF}
\usepackage{amsmath}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}
\begin{document}

\begin{figure}
    \centering
    \begin{tikzpicture}
        \node[] (cold_in) at (5,0) {};
        \node[] (cold_out) at (0,0) {};
        \draw[gray] (cold_out) -- (cold_in);
        \node[anchor=north west,rectangle] (T_C) at (cold_in.south east) {$T_{C,L}$};
        \node[anchor=north east,rectangle] (T_zero) at (cold_out.south west) {$T_0$};

        \draw[->,dotted] (T_C) -- (T_zero);
        
        \node[anchor=north west] (hot_in) at (T_zero.south east) {};
        \node[anchor=north east] (hot_out) at (T_C.south west) {};
        \draw[red] (hot_out) -- (hot_in);
    \end{tikzpicture}
\end{figure}
\end{document}

Answer 1

您可以使用以下（简单、简短的）代码绘制节点之间带有直线的图像：

\documentclass[12pt, margin=3mm]{standalone}
\usepackage{tikz}
% commented libraries and packages are not needed in this example
\usetikzlibrary{arrows.meta,    
                %calc,
                %intersections,,
                %shapes,
                %patterns, patterns.meta, positioning,
                %quotes,
                %shapes.misc, shapes.geometric
                }
%\definecolor{viola}{HTML}{8100FF}
%\usepackage{amsmath}

\begin{document}

    \begin{tikzpicture}[
N/.style = {minimum height=3ex, text depth=0.25ex},
shorten <>/.style = {shorten > = #1, shorten <=#1}
                        ]
\node (cold_in)     [N, right] at (5,0) {$T_{C,L}$};
\node (cold_out)    [N,  left] at (0,0) {$T_0$};

\draw[gray, shorten <>=3mm] (cold_out.north east) -- (cold_in.north west);
\draw[red,  shorten <>=3mm] (cold_out.south east) -- (cold_in.south west);
\draw[-Straight Barb,dotted] (cold_in) -- (cold_out);
    \end{tikzpicture}
 
\end{document}

Answer 2

我建议稍微简化它，但仍然使用节点的锚点。

\documentclass[12pt]{article}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,shapes,positioning,intersections,quotes,patterns,patterns.meta,shapes.misc,shapes.geometric,calc}
\definecolor{viola}{HTML}{8100FF}
\usepackage{amsmath}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}
\begin{document}

\begin{figure}
    \centering
    \begin{tikzpicture}
        \node[above left,minimum height=1cm,inner ysep=0pt] (T_C) at (5,0) {$T_{C,L}$};
        \node[above right,minimum height=1cm,inner ysep=0pt] (T_zero) at (0,0) {$T_0$};

        \draw[->,dotted] (T_C) -- (T_zero);
        
        \node[anchor=north west] (hot_in) at (T_zero.south east) {};
        \node[anchor=north east] (hot_out) at (T_C.south west) {};
        \draw[gray] (T_zero.north east) -- (T_C.north west);
        \draw[red] (T_zero.south east) -- (T_C.south west);
    \end{tikzpicture}
\end{figure}
\end{document}