3D plot of a surface defined by a function
fplot3d(xr,yr,f,[theta,alpha,leg,flag,ebox])
fplot3d(xr,yr,f,<opt_args>)
:xr row vector of size n1. : :yr row vector of size n2. : :f external of type z=f(x,y). : :theta,alpha,leg,flag,ebox see plot3d. : :<opt_args> see plot3d. :
fplot3d plots a surface defined by the external function f on the grid defined by xr and yr.
Enter the command fplot3d() to see a demo.
`deff`_('z=f(x,y)','z=x^4-y^4')
x=-3:0.2:3 ;y=x ;
`clf`_() ;fplot3d(x,y,f,alpha=5,theta=31)