XRAY must be a dummy vector. Y1RAY must be a dummy vector. XRAY and Y1RAY must be dummy arrays. Bars can be plotted on top of one another if the routine BARS is called several times. 3 NGRP is the number of bars defining one group.
GAP defines the spacing between group bars.
If GAP is negative, the positive value of GAP is used where GAP must be specified in plot coordinates. Different colours can be defined for the sides of 3-D bars. The value -1 means that the corresponding plane is plotted with the current colour. 3 IC is a colour number between -1 and 255. 3 XF is a floatingpoint number that defines the depth of bars.