数控插补程序，直线插补和圆弧插补，1．直线插补：逐点比较法插补；2． 圆弧插补：DDA法插补第一、二象限的逆圆弧-NC interpolation procedures, linear interpolation and circular interpolation, 1. Linear interpolation: by-point comparison interpolation 2. Circular interpolation: DDA interpolation method fir