plbin.3plplot man page

plbin — Plot a histogram from binned data


plbin(nbin, x, y, opt)


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(3plplot) for drawing histograms from unbinned data.

Redacted form:  General: plbin(x, y, opt) Perl/PDL: plbin(nbin, x, y, opt) Python: plbin(nbin, x, y, opt)

This function is not used in any examples.


nbin (PLINT, input)

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

x (const PLFLT *, input)

Pointer to array containing values associated with bins.  These must form a strictly increasing sequence.

y (const 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).


Many developers (who are credited at have contributed to PLplot over its long history.

See Also

PLplot documentation at


August, 2015 PLplot API