plgzax: Get z axis parameters 

DESCRIPTION:

    Identical to plgxax, except that arguments are flags for z axis. See
    the description of plgxax for more detail. 

SYNOPSIS:

plgzax(digmax, digits)

ARGUMENTS:

    digmax (PLINT *, output) :      Pointer to variable with the maximum
    number of digits for the z axis.  If nonzero, the printed label
    has been switched to a floating point representation when the
    number of digits exceeds digmax. 

    digits (PLINT *, output) :      Pointer to variable with the actual
    number of digits for the numeric labels (z axis) from the last
    plot.