hbars(yy, xx, h) draws a horizontal bar graph of data xx at yy with bars of width h (in the vertical direction), specified in data coordinates.
hbars(yy, xx, h, x0) specifies a nonzero baseline of the plot.
x0 may also be a vector, which must be the same length as xx and yy. This is useful for creating stacked bar graphs. Note that xx is never relative to x0.
If h is not given, it defaults to mean(diff(yy)).
If the length of the yy vector is one greater than the length of the xx vector, the yy vector is taken to represent the edges of the bins.