
plaxes: Draw a box with axes, etc. with arbitrary
origin 

DESCRIPTION:

    Draws a box around the currently defined viewport with arbitrary
    world-coordinate origin specified by x0 and y0 and labels it with
    world coordinate values appropriate to the window.	Thus plaxes should
    only be called after defining both viewport and window.  The character
    strings xopt and yopt specify how the box should be drawn as described
    below.  If ticks and/or subticks are to be drawn for a particular
    axis, the tick intervals and number of subintervals may be specified
    explicitly, or they may be defaulted by setting the appropriate
    arguments to zero. 

SYNOPSIS:

plaxes(x0, y0, xopt, xtick, nxsub, yopt, ytick, nysub)

ARGUMENTS:

    x0 (PLFLT, input) :    World X coordinate of origin. 

    y0 (PLFLT, input) :    World Y coordinate of origin. 

    xopt (const char *, input) :    Pointer to character string specifying
    options for horizontal 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. 
        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). 
        s: Enables subticks between major ticks, only valid if t is
        also specified. 
        t: Draws major ticks. 


    xtick (PLFLT, input) :    World coordinate interval between major
    ticks on the x axis. If it is set to zero, PLplot automatically
    generates a suitable tick interval. 

    nxsub (PLINT, input) :    Number 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 (const char *, input) :    Pointer to character string specifying
    options for vertical axis.  The string can include any combination
    of the letters defined above for xopt, and in addition may
    contain: v: Write numeric labels for vertical axis parallel to the
    base of the graph, rather than parallel to the axis. 


    ytick (PLFLT, input) :    World coordinate interval between major
    ticks on the y axis. If it is set to zero, PLplot automatically
    generates a suitable tick interval. 

    nysub (PLINT, input) :    Number of subintervals between major y axis
    ticks for minor ticks.    If it is set to zero, PLplot automatically
    generates a suitable minor tick interval. 
