![绘制两条斜率不同的直线](https://linux22.com/image/384373/%E7%BB%98%E5%88%B6%E4%B8%A4%E6%9D%A1%E6%96%9C%E7%8E%87%E4%B8%8D%E5%90%8C%E7%9A%84%E7%9B%B4%E7%BA%BF.png)
答案1
这是绘制的版本元帖子- 一种嵌入在 Context 和 LuaLatex 包中的绘图语言luamplib
。
\documentclass[border=5mm]{standalone}
\usepackage{luatex85}
\usepackage{luamplib}
\begin{document}
\mplibtextextlabel{enable}
\begin{mplibcode}
beginfig(1);
% define some points
z0 = (0, 30);
z1 = (50, 80);
z2 = (140, 100);
% and three paths
path xx, yy, ff;
ff = z0 -- z1 -- z2;
xx = origin -- (x2, 0);
yy = xx rotated 90;
% draw the paths + the dashed line
draw (x1, 0) -- z1 dashed evenly;
draw ff withcolor 3/4 green;
draw xx withcolor 2/3 blue;
draw yy withcolor 2/3 blue;
% some regular labels
label.top("$\alpha, \phi_c$", point 1 of yy);
label.bot("$a_5$", (x1, 0));
label.bot("$\phi_e$", 1/2(x1+x2, 0));
% rotated labels are a little more complicated
label(textext("$a_1 + a_2(\phi)$") rotated angle direction 1/2 of ff,
point 1/2 of ff shifted (7 up rotated angle direction 1/2 of ff));
label(textext("$a_3 + a_4(\phi)$") rotated angle direction 3/2 of ff,
point 3/2 of ff shifted (7 up rotated angle direction 3/2 of ff));
endfig;
\end{mplibcode}
\end{document}