设计滤波器：设定10个零点，计算出多项式系数，作为滤波器系数； 取出绝对值较大的一半零点，重新设计滤波器；用剩下的绝对值较小的一半零点，重新设计滤波器。-Design a filter: Set of 10 zeros, calculate the polynomial coefficients as filter coefficients　remove the larger half of the absolute value of zero, re-design filter　with the remaining half of the smaller absolute zero, re-design filter.