anchor.diff:     ! would be domega = 0.)
      domega = 0.05
      call pladv(0)
  -   call plvpor(-0.15, 1.15, -0.05, 1.05)
  -   call plwind(-1.2, 1.2, -0.8, 1.5)
  -   call plw3d(1.0, 1.0, 1.0, xmin, xmax, ymin, ymax, zmin, zmax, 20., 45.)
  +   call plvpor(-0.15_plflt, 1.15_plflt, -0.05_plflt, 1.05_plflt)
  +   call plwind(-1.2_plflt, 1.2_plflt, -0.8_plflt, 1.5_plflt)
  +   call plw3d(1.0_plflt, 1.0_plflt, 1.0_plflt, xmin, xmax, ymin, ymax, &
  +        zmin, zmax, 20._plflt, 45._plflt)
   
      call plcol0(2)
      call plbox3("b",   "", xmax-xmin, 0, &
  
positive.code:    real(PLFLT), dimension(:), allocatable   :: x, y
     real(PLFLT), dimension(:,:), allocatable :: z
  
     real(PLFLT) :: xmin=0., xmax=1.0, xmid = 0.5*(xmax + xmin), xrange = xmax - xmin, &
                    ymin=0., ymax=1.0, ymid = 0.5*(ymax + ymin), yrange = ymax - ymin, &
                    zmin=0., zmax=1.0, zmid = 0.5*(zmax + zmin), zrange = zmax - zmin, &
                    x_inclination, y_inclination, z_inclination,                       &
                    x_shear, y_shear, z_shear,                                         &
                    omega, sin_omega, cos_omega, domega
     integer     :: i, j
     real(PLFLT) :: radius, pitch, xpos, ypos, zpos
  
     character(len=1)  :: p1string = "O"
     character(len=80) :: pstring  = &
       *pstring = "The future of our civilization depends on software freedom."
  
     ! Allocate and define the minimal x, y, and z to insure 3D box
     allocate( x(XPTS) )
  
negative.code:    ! Page 1: Demonstrate inclination and shear capability pattern.
  
     call pladv(0)
     call plvpor(-0.15_plflt, 1.15_plflt, -0.05_plflt, 1.05_plflt)
     call plwind(-1.2_plflt, 1.2_plflt, -0.8_plflt, 1.5_plflt)
     call plw3d(1.0_plflt, 1.0_plflt, 1.0_plflt, xmin, xmax, ymin, ymax, zmin, zmax, 20._plflt, 45._plflt)
  
     call plcol0(2)
     call plbox3("b",   "", xmax-xmin, 0, &
  