求Dalao告诉我FFT如何求幅值相位等等

我用
#define PI 3.1415926

#define X2D (PI / 180.0)
#define A 97.14
#define Q (12.37 * X2D)
#define DD (360.0 / 1024.0)

while (1024 > iCounter)
{
    in[iCounter][0] = (double)(A * sin((((double)iCounter) * DD * X2D) + Q));
    in[iCounter][1] = 0.0;
    //pData[iCounter] = (double)(A * sin((((double)iCounter) * DD * X2D) + Q));
    iCounter++;
}

创建一个波形，然后用FFTW
    fftw_plan plan;

plan = fftw_plan_dft_1d(1024, in, out, FFTW_FORWARD, FFTW_ESTIMATE);

fftw_execute(plan);
进行FFT

之后
for (iCounter = 0; iCounter < 200; iCounter++)
{
    double dT = sqrt(out[iCounter][0] * out[iCounter][0] + out[iCounter][1] * out[iCounter][1]);
    printf("%lf\n", dT);
    if (dT > AM)
    {
        AM = dT;
    }
}

得到的时49735这样的值。请问我是不是哪里错了？
另怎么从FFT结果中求得A，Q等值？

https://www.amobbs.com/thread-4991984-1-1.html?_dsign=9c539281