The xyerrorlines style is only relevant to 2D data plots. xyerrorlines is like linespoints, except that horizontal and vertical error bars are also drawn. At each point (x,y), lines are drawn from (x,y-ydelta) to (x,y+ydelta) and from (x-xdelta,y) to (x+xdelta,y) or from (x,ylow) to (x,yhigh) and from (xlow,y) to (xhigh,y), depending upon the number of data columns provided. The appearance of the tic mark at the ends of the bar is controlled by set errorbars. Either 4 or 6 input columns are required.
4 columns: x y xdelta ydelta 6 columns: x y xlow xhigh ylow yhigh
If data are provided in an unsupported mixed form, the using filter on the plot command should be used to set up the appropriate form. For example, if the data are of the form (x,y,xdelta,ylow,yhigh), then you can use
plot 'data' using 1:2:($1-$3):($1+$3):4:5 with xyerrorlines
An additional input column (5th or 7th) may be used to provide variable (per-datapoint) color information.