initial commit

2026-09-17 22:49:08 +09:00 · 2026-08-07 15:56:42 +09:00
commit 91ad25aca9
1012 changed files with 159314 additions and 0 deletions
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+from numpy import *
+from numpy.fft import *
+import pyfftw
+
+class shift_fftw:
+      """Shift function via FFT"""
+      def __init__(self, dk_x, dk_y, N):
+          kx = linspace(-floor(N/2.0),ceil(N/2.0)-1,N)
+          kx = ifftshift(kx)
+          [self.kX, self.kY] = meshgrid(kx,kx)
+          self.kX = self.kX*dk_x
+          self.kY = self.kY*dk_y
+          self.f = pyfftw.empty_aligned((N,N),dtype='complex128',n=16) 
+          self.r = pyfftw.empty_aligned((N,N),dtype='complex128',n=16)
+          self.N_tot = N*N
+          self.fft_forward = pyfftw.FFTW(self.r, self.f, axes=(0,1))
+          self.fft_inverse = pyfftw.FFTW(self.f, self.r, direction='FFTW_BACKWARD', axes=(0,1))
+
+      def shift(self, func, px, py):
+          self.r[:,:] = ifftshift(func)
+          self.fft_forward.update_arrays(self.r, self.f)
+          self.fft_forward.execute()
+          self.f = self.f*exp(-2*pi*1j*px*self.kX)*exp(-2*pi*1j*py*self.kY)
+          self.fft_inverse.update_arrays(self.f, self.r)
+          self.fft_inverse.execute();
+          return fftshift(self.r) / self.N_tot #fix normalization