plw3d: Set up window for 3-d plotting 

DESCRIPTION:

    Sets up a window for a three-dimensional surface plot within the
    currently defined two-dimensional window.  The enclosing box for the
    surface plot defined by xmin, xmax, ymin, ymax, zmin and zmax in
    user-coordinate space is mapped into a box of world coordinate size
    basex by basey by height so that xmin maps to -
    basex/2, xmax maps to basex/2, ymin maps to -
    basey/2, ymax maps to basey/2, zmin maps to 0 and zmax maps to height.
     The resulting world-coordinate box is then viewed by an observer at
    altitude alt and azimuth az.  This routine must be called before
    plbox3 or plot3d.  For a more complete description of
    three-dimensional plotting see the PLplot documentation. 

SYNOPSIS:

plw3d(basex, basey, height, xmin, xmax, ymin, ymax, zmin, zmax, alt, az)

ARGUMENTS:

    basex (PLFLT, input) :    The x coordinate size of the
    world-coordinate box. 

    basey (PLFLT, input) :    The y coordinate size of the
    world-coordinate box. 

    height (PLFLT, input) :    The z coordinate size of the
    world-coordinate box. 

    xmin (PLFLT, input) :    The minimum user x coordinate value. 

    xmax (PLFLT, input) :    The maximum user x coordinate value. 

    ymin (PLFLT, input) :    The minimum user y coordinate value. 

    ymax (PLFLT, input) :    The maximum user y coordinate value. 

    zmin (PLFLT, input) :    The minimum user z coordinate value. 

    zmax (PLFLT, input) :    The maximum user z coordinate value. 

    alt (PLFLT, input) :    The viewing altitude in degrees above the xy
    plane. 

    az (PLFLT, input) :    The viewing azimuth in degrees.  When az=0, the
    observer is looking face onto the zx plane, and as az is
    increased, the observer moves clockwise around the box when viewed
    from above the xy plane.