// Calculates measured and theoretical area of elliptical selections with diameters // varying from 1 to 500 pixels, and displays the difference as a percentage. max= 500; newImage("Test", "8-bit", max, max, 1); for (diameter=1; diameter<=max; diameter++) { makeOval(0, 0, diameter, diameter); run("Measure"); area1 = getResult("Area", nResults-1); radius = diameter/2; area2 = PI*radius*radius; difference = ((area2-area1)/area1)*100; print(diameter+" "+area1+" "+area2+" "+difference); } selectWindow("Test"); run("Close");