;$Id: phel12.pro,v 1.3 2016/07/26 13:28:04 brandenb Exp $
;
;  reads bb.sav, Fourier transforms, and saves result in bbk.sav
;  This is the version *with* domain doubling in the z direction.
;  It uses forward FFT with exp(+ikz), so HM(k3)=BxBy^*.
;
restore,'data/bb.sav'
;
s=size(bb) & nx=s[1] & ny=s[2] & nz=s[3] & nz2=nz*2
n=nx*ny*nz2 & print,nx,ny,nz2
tmp=fltarr(nx,ny,nz2)
;
tmp[*,*,0:nz-1]=bb[*,*,*,0]
tmp[*,*,nz:nz2-1]=bb[*,*,*,0]
b1k=fft(tmp,+1)/n
;
tmp[*,*,0:nz-1]=bb[*,*,*,1]
tmp[*,*,nz:nz2-1]=bb[*,*,*,1]
b2k=fft(tmp,+1)/n
;
tmp[*,*,0:nz-1]=bb[*,*,*,2]
tmp[*,*,nz:nz2-1]=bb[*,*,*,2]
b3k=fft(tmp,+1)/n
tmp=0.
bb=0.
;
;  shift to corner
;
b1k=shift(b1k,nx/2,ny/2,nz2/2)
b2k=shift(b2k,nx/2,ny/2,nz2/2)
b3k=shift(b3k,nx/2,ny/2,nz2/2)
;
save,file='data/bbk2.sav',b1k,b2k,b3k,nx,ny,nz,nz2,t
;
end