中文说明：求频响函数的实频、虚频、幅频、相频及Nyqiust图！在读取实验所得振动数据后，通过程序提取模态特性，利用拟合圆法，求三阶固有频率、阻尼比。计算各阶主振型。
English Description：
Find the real frequency of the frequency response function and imaginary frequency, amplitude, phase frequency and Nyqiust diagram! Reading after experimental vibration data obtained through program extract modal characteristics using fitting method, and third-order natural frequency and damping ratio. Calculate principal mode of each order.