| 
            plsurf3d
          ( | x , | 
| y , | |
| z , | |
| nx , | |
| ny , | |
| opt , | |
| clevel , | |
| nlevel ); | 
      Plots a three-dimensional shaded surface plot within the environment set up
      by plw3d.  The surface is defined by the two-dimensional matrix
      z[nx][ny]z[i][j](.
      Note that the points in vectors x[i],y[j])xy
x
          (PLFLT_VECTORA vector containing the x coordinates at which the function is evaluated.
y
          (PLFLT_VECTORA vector containing the y coordinates at which the function is evaluated.
z
          (PLFLT_MATRIX
	    A matrix containing function values to plot.  Should have
	    dimensions of nx by ny.
          
nx
          (PLINT
            Number of x
ny
          (PLINT
            Number of y
opt
          (PLINTDetermines the way in which the surface is represented. To specify more than one option just add the options, e.g. FACETED + SURF_CONT
                  
                    : Network
                  of lines is drawn connecting points at which function is
                  defined.
                opt=FACETED
                  
                  
                    : A contour
                  plot is drawn at the base XY plane using parameters
                  opt=BASE_CONT
                  nlevel and clevel.
                
                  
                    : A contour
                  plot is drawn at the surface plane using parameters
                  opt=SURF_CONT
                  nlevel and clevel.
                
                  
                    : draws a curtain
                  between the base XY plane and the borders of the plotted function.
                opt=DRAW_SIDES
                  
                  
                    :
                  the surface is colored according to the value of Z; if
                  opt=MAG_COLOR
                  MAG_COLOR is not used, then
                  the surface is colored according to the intensity of the
                  reflected light in the surface from a light source whose
                  position is set using pllightsource.
                
clevel
          (PLFLT_VECTORA vector containing the contour levels.
nlevel
          (PLINT
            Number of elements in the clevel vector.
          
      Redacted form: plsurf3d(x, y, z, opt, clevel)
    
This function is not used in any examples.