[求助] 怎样画一个柱面？

roll66

请教：已知一个隐函数F（x, y ）=0,要画它在三维空间的柱面，怎么画啊？<BR><BR> 谢谢大家指教！！

yqchenlolo

  f=inline('x^2+y^2-1');<BR>  fvector=vectorize(f);<BR>  x=linspace(-1,1);<BR>  y=x;<BR>  z=x;<BR>  [xm,ym,zm]=meshgrid(x,y,z);<BR>  fvalues=feval(fvector,xm,ym);<BR>  isosurface(xm,ym,zm,fvalues,0);<BR>我记得好像有个画柱面的函数，忘记了，你自己google一下吧

roll66

<P>谢谢yqchenlolo, 有个画旋转曲面的命令cylinder,<BR>isosurface(xm,ym,zm,fvalues,0) 中，最后一个零表示什么？<BR>看了帮助文件没看明白。  <BR><BR></P>

happy

In a contour plot, the contour value determines where you're "slicing" your<BR>surface -- if your contour value is 2 then you're taking a look at the set<BR>of x and y values where f(x, y) = 2 [where z = f(x, y)]. An isosurface is<BR>just a contour plot but with one higher dimension, and the isovalue is the<BR>contour value for the isosurface. So if your isovalue is 3, and the<BR>hypersurface for which you're computing the isosurface is v = f(x, y, z),<BR>the isosurface is the set of x, y, and z values for which f(x, y, z) = 3.<BR>

yqchenlolo

<DIV class=quote><B>以下是引用<I>roll66</I>在2006-3-13 18:23:47的发言：</B><BR>
<P>谢谢yqchenlolo, 有个画旋转曲面的命令cylinder,<BR>isosurface(xm,ym,zm,fvalues,0) 中，最后一个零表示什么？<BR>看了帮助文件没看明白。  <BR><BR></P></DIV>
<P>isosurface(xm,ym,zm,fvalues,d)这里表示画f(x,y)=d的柱面</P>

阿sa

请问怎么画F(x,y,z)=0的三维图呢？:@)

sigma665

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