Up: Set style rectangle
The xerrorbars style is only relevant to 2-d data plots. xerrorbars is
like dots, except that a horizontal error bar is also drawn. At each point
(x,y), a line is drawn from (xlow,y) to (xhigh,y) or from (x-xdelta,y) to
(x+xdelta,y), depending on how many data columns are provided. A tic mark
is placed at the ends of the error bar (unless set bars is used -- see
set bars (p. ) for details).