//復數的模，模值*N/2 對應該頻率下信號的幅度，模值/N直流信號幅度 s1[i].real=sqrtf(s1[i].real*s1[i].real+s1[i].imag*s1[i].imag); s2[i].real=sqrtf(s2[i].real*s2[i].real+s2[i].imag*s2[i].imag); //printf("%d\n",s1[i].real); } s1_max_index = find_max_num_index(s1, 60); //最大幅度值為第幾個 s2_max_index