Question

matlab如何画出下面的图像 (x^2+9/4*y^2+z^2-1)^3-x^2*z^3-9/80*y^2*z^3=0

Answer 1

f=@(x,y,z)(x.^2+9/4*y.^2+z.^2-1).^3-x.^2.*z.^3-9/80*y.^2.*z.^3

 implicitmesh(f,[-5 5],150)

-----------------------------

function h=implicitmesh(f,xlimit,ylimit,zlimit,gd)

%implicitmesh(f,span,gd):画隐函数曲面f(x,y,z)=0的网格图,

%                          各坐标范围均限定在span=[lb,ub],

%                          网格数为gd，默认为25

if nargin==2

    ylimit=xlimit;zlimit=xlimit;gd=25;

elseif nargin==3

    gd=ylimit;ylimit=xlimit;zlimit=xlimit;

elseif nargin==4

    gd=25;

elseif nargin==5

else

    error('Error in input arguments')

end

x=linspace(xlimit(1),xlimit(2),gd);

y=linspace(ylimit(1),ylimit(2),gd);

z=linspace(zlimit(1),zlimit(2),gd);

[x,y,z]=meshgrid(x,y,z);val=f(x,y,z);

[f,v]=isosurface(x,y,z,val,0);

if isempty(f)

    warning('There is no graph in the range.');

    p=[];

else

    newplot;

    p=patch('Faces',f,'Vertices',v,'CData',v(:,3),'facecolor','w','EdgeColor','flat');

    isonormals(x,y,z,val,p);view(3);grid on

end

if nargout==0

else

    h=p;

end