It is commonly known as MAGIC CIRCLE GENERATOR. It is useful for small micro-controllers with small memory. Especially when SIN OR COS trigonometric functions are unavailable. Here is a slightly different version of the common MAGIC CIRCLE. This version is suitable for symmetric synchronous updates and avoids the ripple problem seen in common implementations. This arrangement can behave as a digital resonator. It requires relatively simple arithmetic. This algorithm relates x and y coordinates of equally spaced points along a circle. It can also be used to compute trigonometric functions of any angle.
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