initial commit

ptycho/utils_electron/shift.m

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+function [ output] = shift( input,dx_x,dx_y,px,py )
+%UNTITLED Summary of this function goes here
+%   Detailed explanation goes here
+
+
+Ny = size(input,1);
+Nx = size(input,2);
+
+dk_y = 1/(dx_y*Ny);
+dk_x = 1/(dx_x*Nx);
+
+ky = linspace(-floor(Ny/2),ceil(Ny/2)-1,Ny);
+kx = linspace(-floor(Nx/2),ceil(Nx/2)-1,Nx);
+
+[kX,kY] = meshgrid(kx,ky);
+kX = kX.*dk_x;
+kY = kY.*dk_y;
+
+f = fftshift(fft2(ifftshift(input)));
+f = f.*exp(-2*pi*1i*px*kX).*exp(-2*pi*1i*py*kY);
+output = fftshift(ifft2(ifftshift(f)));
+
+end