
plbin: Plot a histogram from binned data 

DESCRIPTION:

    Plots a histogram consisting of nbin bins.	The value associated with
    the i'th bin is placed in x[i], and the number of points in the bin is
    placed in y[i].  For proper operation, the values in x[i] must form a
    strictly increasing sequence.  By default, x[i] is the left-hand edge
    of the i'th bin. If opt=PL_BIN_CENTRED is used, the bin boundaries are
    placed midway between the values in the x array.  Also see plhist for
    drawing histograms from unbinned data. 

SYNOPSIS:

plbin(nbin, x, y, opt)

ARGUMENTS:

    nbin (PLINT, input) :    Number of bins (i.e., number of values in x
    and y arrays.) 

    x (PLFLT *, input) :    Pointer to array containing values associated
    with bins.  These must form a strictly increasing sequence. 

    y (PLFLT *, input) :    Pointer to array containing number of points
    in bin.  This is a PLFLT (instead of PLINT) array so as to allow
    histograms of probabilities, etc. 

    opt (PLINT, input) :    Is a combination of several flags:
    opt=PL_BIN_DEFAULT: The x represent the lower bin boundaries, the
    outer bins are expanded to fill up the entire x-axis and bins of
    zero height are simply drawn. 
        opt=PL_BIN_CENTRED|...: The bin boundaries are to be midway
        between the x values. If the values in x are equally spaced,
        the values are the center values of the bins. 
        opt=PL_BIN_NOEXPAND|...: The outer bins are drawn with equal
        size as the ones inside. 
        opt=PL_BIN_NOEMPTY|...: Bins with zero height are not drawn
        (there is a gap for such bins). 
