如何在图片环境中制作抛物线和直线？

Question

我想使用pictureLaTeX 环境制作这张图片，但我不知道该怎么做。

Answer 1

该picture环境可能不是绘制抛物线图的典型工具，但因为您要求它：

\documentclass{article}

\usepackage{xcolor}

\begin{document}

\setlength{\unitlength}{1.5cm}
\begin{picture}(4,3)

\put(0,0){\vector(1,0){4}}
\put(0,0){\vector(0,1){3}}
\put(0,0){\line(2,1){3.5}}

{%
\thicklines
\color{blue}%
\qbezier(0,0)(1.5,3)(3,1.5)
}

\put(-0.25,2.9){y}
\put(3.9,-0.25){x}
\put(3.1,1.3){(x,y)}
\put(1.5,1){R}

{%
\color{orange}%
\multiput(3,0)(0,0.2){8}{\line(0,1){0.1}}
}

\qbezier(0.8,0)(0.8,0.2)(0.7,0.34)
\put(0.9,0.1){$\Phi$}

\qbezier(0.71,0)(0.7,0.35)(0.35,0.6)
\put(0.3,0.3){$\Theta$}

{%
\color{orange}%
\multiput(0,0)(0.25,0.5){6}{\line(1,2){0.12}}
}
\end{picture}

\end{document}