Problem Find area surface

Question

justin Taylor 2011-12-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/23014-problem-find-area-surface

采纳的回答： Walter Roberson

x = ( 1-u )(3+cos v)cos(2pi*u)

y = ( 1-u )(3+cos v)sin(2pi*u)

z = 4u + ( 1-u )sinv.

D={(u,v)|0<=u<=1,0<=v<=2pi}

http://i1203.photobucket.com/albums/bb396/kidstar079/Capture-1.png

mycode

{ syms u v;

x = (1-u).*(3+cos(v)).*cos(pi*u);

y = (1-u).*(3+cos(v)).*sin(pi*u);

z = 8*u+( 1-u ).*sin(v);

F=[x,y,z];

ru=diff(F,[u]);

rv=diff(F,[v]);

ruv=ru.*rv;

druv=sqrt(ruv(1).^2+ruv(2).^2+ruv(3).^2);

S=int(int(druv,u,0,1),v,0,2*pi)

}

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Jan 2011-12-5

Please, Anh Em, stop sending me emails. This is a public forum and it lives on the idea that all information are shared.

Whenever I know an answer, I take the time to post it here. Therefore there is no reason to push me by emails. In opposite: it is annoying, and therefore a bad idea, if you want to get an answer.

As Walter I suggest to read: http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer and

http://www.mathworks.com/matlabcentral/answers/8626-how-do-i-get-help-on-homework-questions-on-matlab-answers

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Answer 1

Walter Roberson 2011-12-4

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/23014-problem-find-area-surface#answer_30254

This is a curved horn that is not self intersecting. You can drop the z coordinate and simply integrate the circumference of the circle with radius (1-u)*(3+cos(v)) over your u, v.