![弗拉姆的抛物面图](https://linux22.com/image/459882/%E5%BC%97%E6%8B%89%E5%A7%86%E7%9A%84%E6%8A%9B%E7%89%A9%E9%9D%A2%E5%9B%BE.png)
如何绘制 弗拉姆抛物面?
tikz、pstricks、metapost、渐近线
\documentclass[12pt]{article}
\usepackage{mathtools,amssymb}
\usepackage{pgfplots}
\pgfplotsset{compat=newest,width=8cm}
\begin{document}
The spatial curvature of the Schwarzschild solution for $r > r_s$ .....
$w=2\sqrt{r_s(r-r_w)}$
For this exemple: w=z, r_s=y and r=x.
\begin{tikzpicture}
\begin{axis}
\addplot3{2*sqrt(y*(x-y))};
\end{axis}
\end{tikzpicture}
\end{document}
答案1
我对这个表面,即弗拉姆抛物面不太熟悉,但我会想到类似这样的东西,假设该方程使用圆柱极坐标:
\documentclass[12pt]{article}
\usepackage{pgfplots}
\pgfplotsset{compat=newest,width=8cm}
\begin{document}
The spatial curvature of the Schwarzschild solution for $r>r_s\ldots$
\[w=2\sqrt{r_s(r-r_s)}.\]
For this example: $w=z$ and $r_s=1$.
\begin{figure}[ht]\centering
\begin{tikzpicture}
\begin{axis}
\addplot3[surf,domain=1:10,domain y=0:2*pi,samples=31] ({\x*cos(\y r)},{\x*sin(\y r)},{2*sqrt(\x-1)});
\end{axis}
\end{tikzpicture}
\caption{Flamm's paraboloid.}
\end{figure}
\end{document}