AnalysisFunctions.py 文件源码

def Spec2D(ar,ax=2,lenx=2*pi,leny=2*pi,lenz=2*pi):
   """
      Spec2D(ar,ax=2,lenx=2*pi,leny=2*pi,lenz=2*pi)

      2D spectrum of ar perpendicular to axis ax

   """
   if len(ar) == 0:
      print 'No array provided! Exiting!'
      return
   ar=ar-np.mean(ar)
   nx=np.shape(ar)[0];kx=nf.fftshift(nf.fftfreq(nx))*nx*(2*pi/lenx)
   ny=np.shape(ar)[1];ky=nf.fftshift(nf.fftfreq(ny))*ny*(2*pi/leny)
   nz=np.shape(ar)[2];kz=nf.fftshift(nf.fftfreq(nz))*nz*(2*pi/lenz)

   if ax==0:
      k1=ky; k2=kz
   elif ax==1:
      k1=kx; k2=kz
   elif ax==2:
      k1=kx; k2=ky

   far = nf.fftshift(nf.fftn(ar))/(nx*ny*nz); fftea=0.5*np.abs(far)**2
   ffteb=fftea.sum(axis=ax)
   return k1,k2,ffteb

##
## 2D SPECTRUM OF A VECTOR
##