qcbarh(w, h) adds a horizontal color bar of given width and height (in points) at the position specified by qat. w may be positive or negative. In either case, the color scale runs from left to right.
qcbarh(w, h, 'l') makes the color scale run right-to-left.
qcbarh(w, h, dx, dy) or qcbarh(w, h, dx, dy, 'l') shifts the bar by the given number of points to the right and down.
qcbarh(w, [], dw) or qcbarh(w,[], dx, dy, dw) specifies the width in data coordinates instead. In this case, the color scale runs l->r (r->l) if dw is positive (negative).
This command only works after a previous qimsc.
qvcbar and qhcbar offer the same functionality with an easier interface.
See also qcaxis.