画出三维曲线z^2=x^3+6*x*y+y^4+6*x+2*y-1 的图像.用matlab绘制

f=@(x,y,z)x。^3+6*x。*y+y。^4+6*x+2*y-1-z。^2; h=implicitsurf(f,[-5 5]);----------------------------------------------function h=implicitsurf(f,xlimit,ylimit,zlimit,gd)%implicitsurf(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%implicitsurf(f,xspan,yspan,zspan,gd):画隐函数曲面f(x,y,z)=0,%                          各坐标范围分别限定在xspan,yspan,zspan%h=implicitsurf(。。。)：画隐函数曲面并输出句柄%例一：%implicitsurf(inline('x。*y+z。^2'),[-5 5])%注意*\^一定要设成点运算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==5else    error('Error in input arguments')endx=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','flat','EdgeColor','k');    isonormals(x,y,z,val,p);view(3);grid onendif nargout==0else    h=p;end