eval3dp
=======

compute facets of a 3D parametric surface



Calling Sequence
~~~~~~~~~~~~~~~~


::

    [Xf,Yf,Zf]=eval3dp(fun,p1,p2)




Arguments
~~~~~~~~~

:Xf,Yf,Zf matrices of size (4,n-1*m-1). `Xf(:,i)` , `Yf(:,i)` and
  `Zf(:,i)` are respectively the x-axis, y-axis and z-axis coordinates
  of the 4 points of the ith four sided facet.
: :fun a Scilab function.
: :p1 a vector of size `n`.
: :p2 a vector of size `m`.
:



Description
~~~~~~~~~~~

`eval3dp` computes a four sided facets representation of a 3D
parametric surface defined by the function `fun`. `fun(p1,p2)`
computes the x-axis ,y-axis and z-axis coordinates of the
corresponding points on the surface, as
[x(i),y(i),z(i)]=fun(p1(i),p2(i)). This is used for efficiency.



Sample
~~~~~~



Examples
~~~~~~~~


::

    p1=`linspace`_(0,2*%pi,10);
    p2=`linspace`_(0,2*%pi,10);
    `deff`_("[x,y,z]=scp(p1,p2)",["x=p1.*sin(p1).*cos(p2)";..
                               "y=p1.*cos(p1).*cos(p2)";..
                               "z=p1.*sin(p2)"])
    [Xf,Yf,Zf]=eval3dp(scp,p1,p2);
    `plot3d`_(Xf,Yf,Zf)




See Also
~~~~~~~~


+ `genfac3d`_ Compute facets of a 3D surface
+ `plot3d`_ 3D plot of a surface


.. _plot3d: plot3d.html
.. _genfac3d: genfac3d.html