FFT Golang 实现

最近项目要用到快速傅立叶变换，自己写了个算法，测试了下，性能和精度还可以接受

len,time= 1048576 378.186167ms

diff=-0.00000000000225974794 I0.00000000000936106748成功: 进程退出代码 0.

百万级别，变换花了378ms

逆变换误差和0.000000000009

 l :=mvm.PowerOf2(20)

   arr :=make([]complex128,l) 

   for i,_ :=range arr{

      arr[i]=complex(rand.Float64(),rand.Float64())

   }

   now :=time.Now()

   fft:= mvm.CoreFFT(arr,false)

   Println("len,time=",l,time.Now().Sub(now))

//   Println("arr=",arr)

//   Println("fft=",fft)

   reverse:=mvm.CoreFFT(fft,true)

   //Println("reverse=",reverse)
   var sumDiff complex128

   for i,v :=range reverse{

      sumDiff =sumDiff+v-arr[i]

   }

   Printf("diff=%.20f I%.20f",real(sumDiff),imag(sumDiff))