Which is more useful nomogram or equation?

We have read the article by Schoen et al. entitled ‘Nomograms for severity of aortic valve using peak aortic valve pressure gradient and left ventricular ejection fraction’.1 The authors have developed a nomogram to quantify the aortic valve area. As the authors have notified, the nomogram has a number of advantages: (a) The errors in measuring the left ventricular outflow tract diameter is eliminated; (b) the systolic function of the left ventricle is taken into consideration; (c) it eliminates the need for the complex computation process of continuity equation. …