| 
	    plbox
	  ( | xopt, | 
| xtick, | |
| nxsub, | |
| yopt, | |
| ytick, | |
| nysub ); | 
      Draws a box around the currently defined viewport, and labels it with
      world coordinate values appropriate to the window.  Thus plbox
      should only be called after defining both viewport and window.  The
      ascii character strings xoptyopt
xopt
	  (PLCHAR_VECTORAn ascii character string specifying options for the x axis. The string can include any combination of the following letters (upper or lower case) in any order:
		  a: Draws axis, X-axis is horizontal
		  line (y=0), and Y-axis is vertical
		  line (x=0).
		
		  b: Draws bottom (X) or left (Y) edge
		  of frame.
		
		  c: Draws top (X) or right (Y) edge of
		  frame.
		
		  d: Plot labels as date / time.
		  Values are assumed to be seconds since the epoch
		  (as used by gmtime).
		
		  f:  Always use fixed point numeric labels.
		
		  g: Draws a grid at the major tick
		  interval.
		
		  h: Draws a grid at the minor tick
		  interval.
		
		  i: Inverts tick marks, so they are
		  drawn outwards, rather than inwards.
		
		  l: Labels axis logarithmically.  This
		  only affects the labels, not the data, and so it is
		  necessary to compute the logarithms of data points before
		  passing them to any of the drawing routines.
		
		  m: Writes numeric labels at major tick
		  intervals in the unconventional location (above box for
		  X, right of box for Y).
		
		  n: Writes numeric labels at major tick
		  intervals in the conventional location (below box for X,
		  left of box for Y).
		
		  o: Use custom labelling function to
		  generate axis label text.  The custom labelling function
		  can be defined with the plslabelfunc command.
		
		  s: Enables subticks between major
		  ticks, only valid if t is also
		  specified.
		
		  t: Draws major ticks.
		
		  u: Exactly like "b" except don't draw edge line.
		
		  w: Exactly like "c" except don't draw edge line.
		
		  x: Exactly like "t" (including the side effect of
		  the numerical labels for the major ticks) except exclude drawing the
		  major and minor tick marks.
		
xtick
	  (PLFLTWorld coordinate interval between major ticks on the x axis. If it is set to zero, PLplot automatically generates a suitable tick interval.
nxsub
	  (PLINTNumber of subintervals between major x axis ticks for minor ticks. If it is set to zero, PLplot automatically generates a suitable minor tick interval.
yopt
	  (PLCHAR_VECTOR
	    An ascii character string specifying options for the y
	    axis.  The string can include any combination of the letters
	    defined above for
	    xopt
		  v: Write numeric labels for the y
		  axis parallel to the base of the graph, rather than
		  parallel to the axis.
		
ytick
	  (PLFLTWorld coordinate interval between major ticks on the y axis. If it is set to zero, PLplot automatically generates a suitable tick interval.
nysub
	  (PLINTNumber of subintervals between major y axis ticks for minor ticks. If it is set to zero, PLplot automatically generates a suitable minor tick interval.
Redacted form:
	    General: plbox(xopt, xtick, nxsub, yopt, ytick, nysub)
	  
This function is used in examples 1, 2, 4, 6, 6-12, 14-18, 21, 23-26, and 29.