private void changeLabel() {
		int label = isOverWhichLabel(mySketch.mouseX, mySketch.mouseY);
		if (label != -1) {
			if (label == X_AXIS) {
				xAttributeIndex++;
				xAttributeIndex %= QuestionData.getFeatureNames().size();
			}
			if (label == Y_AXIS) {
				yAttributeIndex++;
				yAttributeIndex %= QuestionData.getFeatureNames().size();
			}

			updatePlot();
		}
	}