plot3d2
=======

plot surface defined by rectangular facets



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


::

    plot3d2(X,Y,Z [,vect,theta,alpha,leg,flag,ebox])
    plot3d2(X,Y,Z, <opt_args>)




Arguments
~~~~~~~~~

:X, Y, Z: 3 real matrices defining a data structure.
: :vect a real vector.
: :<opt_args> This represents a sequence of statements `key1=value1,
  key2=value2`,... where `key1`, `key2,...` can be one of the following:
  theta, alpha ,leg,flag,ebox (see definition below).
: :theta, alpha real values giving in degree the spherical coordinates
  of the observation point.
: :leg string defining the labels for each axis with @ as a field
  separator, for example "X@Y@Z".
: :flag a real vector of size three. `flag=[mode,type,box]`.
    :mode an integer (surface color).
        :mode>0 the surface is painted with color `"mode"` ; the boundary of
          the facet is drawn with current line style and color.
        : :mode=0: a mesh of the surface is drawn.
        : :mode<0: the surface is painted with color `"-mode"` ; the boundary
          of the facet is not drawn. Note that the surface color treatement can
          be done using `color_mode` and `color_flag` options through the
          surface entity properties (see `surface_properties`_).
        :

    : :type an integer (scaling).
        :type=0: the plot is made using the current 3D scaling (set by a
          previous call to `param3d`, `plot3d`, `contour` or `plot3d1`).
        : :type=1: rescales automatically 3d boxes with extreme aspect ratios,
          the boundaries are specified by the value of the optional argument
          `ebox`.
        : :type=2: rescales automatically 3d boxes with extreme aspect ratios,
          the boundaries are computed using the given data.
        : :type=3: 3d isometric with box bounds given by optional `ebox`,
          similarily to `type=1`.
        : :type=4: 3d isometric bounds derived from the data, to similarily
          `type=2`.
        : :type=5: 3d expanded isometric bounds with box bounds given by
          optional `ebox`, similarily to `type=1`.
        : :type=6: 3d expanded isometric bounds derived from the data,
          similarily to `type=2`. Note that axes boundaries can be customized
          through the axes entity properties (see `axes_properties`_).
        :

    : :box an integer (frame around the plot).
        :box=0: nothing is drawn around the plot.
        : :box=1: unimplemented (like box=0).
        : :box=2: only the axes behind the surface are drawn.
        : :box=3: a box surrounding the surface is drawn and captions are
          added.
        : :box=4: a box surrounding the surface is drawn, captions and axes
          are added. Note that axes aspect can also be customized through the
          axes entity properties (see `axes_properties`_).
        :

    :

: :ebox It specifies the boundaries of the plot as the vector
  `[xmin,xmax,ymin,ymax,zmin,zmax]`. This argument is used together with
  `type` in `flag` : if it is set to `1`, `3` or `5` (see above to see
  the corresponding behaviour). If `flag` is missing, `ebox` is not
  taken into acoount. Note that, when specified, the `ebox` argument
  acts on the `data_bounds` field that can also be reset through the
  axes entity properties (see `axes_properties`_).
:



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

`plot3d2` plots a surface defined by rectangular facets. (X,Y,Z) are
three matrices which describe a surface. The surface is composed of
four sided polygons.

The X-coordinates of a facet are given by X(i,j), X(i+1,j), X(i+1,j+1)
and X(i,j+1). Similarly Y and Z matrices contain Y and Z-coordinates.

The `vect` vector is used when multiple surfaces are coded in the same
(X,Y,Z) matrices. `vect(j)` gives the line at which the coding of the
jth surface begins. Like in `plot3d`, the same properties are editable
(see `surface_properties`_ and `axes_properties`_).



Sample
~~~~~~



Examples
~~~~~~~~


::

    u = `linspace`_(-%pi/2,%pi/2,40);
    v = `linspace`_(0,2*%pi,20);
    X = `cos`_(u)'*`cos`_(v);
    Y = `cos`_(u)'*`sin`_(v);
    Z = `sin`_(u)'*`ones`_(v);
    plot3d2(X,Y,Z);
    e=`gce`_();
    e.color_mode=4; // change color
    f=e.data;
    TL = `tlist`_(["3d" "x" "y" "z" "color"],f.x,f.y,f.z,10*(f.z)+1);
    e.data=TL;
    e.color_flag=2;




See Also
~~~~~~~~


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


.. _genfac3d: genfac3d.html
.. _plot3d: plot3d.html
.. _axes_properties: axes_properties.html
.. _surface_properties: surface_properties.html