public void setUpComparisonBars() {
		overBars.clear();
		underBars.clear();
		float toScale = 0.05f;
		for (int i = 0; i < nbars; i++) {

			int over = beatMarket.histogram[i];
			int under = marketBeat.histogram[i];
			int absDiff = Math.abs(over - under);

			int top = (int) (frameH - SIDE_BUFFER - (int) (toScale * absDiff + 2));
			int left = SIDE_BUFFER + BAR_BUFFER * i + ((int) barwidth) * i;
			int width = (int) (barwidth);
			int height = (int) (toScale * absDiff + 2);
			Rectangle2D.Float diff = new Rectangle2D.Float(left, top, width,
					height);

			if (over > under) {
				// green bar
				overBars.add(diff);
			} else if (under > over) {
				// red bar
				underBars.add(diff);
			}
		}
	}