This statement affects the width and height of shapes subsequently drawn with the CIRCLE statement. By suitably setting the h and v parameters, you can draw ellipses with any aspect ratio. Each of h and v can range in value from -128 to +127. The h parameter affects the width of the ellipse, and the v parameter affects its height. When you subsequently execute a CIRCLE statement with a radius parameter of radius, a circle or ellipse is drawn which has these dimensions: Shape's width = 2 * radius * (1 + h /128) Shape's height = 2 * radius * (1 + v /128) We can notice a few consequences of these formulas: If h and v are equal, a circle is drawn. If h and v are different, an ellipse is drawn. If h > v, the ellipse is wider than it is tall. If v > h, the ellipse is taller than it is wide. Negative values of h or v cause the corresponding dimension to shrink. Positive values cause the corresponding dimension to grow (up to about twice its original size). Specifying RATIO 0,0 "resets" the ratios: subsequent CIRCLE statements will draw a circle with the indicated radius. After you execute a RATIO statement, the indicated h and v values remain in effect for all subsequent CIRCLE statements (in all windows), until another RATIO statement is executed.