computeFXYZ.m
6747c30adba5shear_version

computeFXYZ.m
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			function output=computeFXYZ(gene_data,varargin)
			%Function for antitrasforming a Fourier field to real space
			%
			% INPUTS:
			% gene_data -> 3D field in Fourier
			% x_local -> Fourier in x (1st dim.)
			%
			% [output]=COMPUTEFXYZ(gene_data)

			%%
			if nargin==1
			x_local=1;
			else
			x_local=varargin{1};
			end

			if x_local
			[nx,nky,nz]=size(gene_data);
			%extend to whole ky by imposing reality condition
			ny=2*nky-1;

			if ny~=1
			%note, we need one extra point which we set to zero for the ifft
			spectrumKxKyZ=zeros(nx,ny,nz);
			spectrumKxKyZ(:,1:nky,:)=gene_data(:,:,:);
			spectrumKxKyZ(1,(nky+1):(ny),:)=conj(gene_data(1,nky:-1:2,:));
			spectrumKxKyZ(2:nx,(nky+1):(ny),:)=conj(gene_data(nx:-1:2,nky:-1:2,:));
			else
			%pad with zeros to interpolate on fine scale
			ny=20;
			spectrumKxKyZ=zeros(nx,ny,nz);
			spectrumKxKyZ(:,2,:)=gene_data(:,:,:);
			end
			%inverse fft, symmetric as we are using real data
			spectrumXKyZ=nx*ifft(spectrumKxKyZ,[],1);
			output=ny*ifft(spectrumXKyZ,[],2,'symmetric');
			clear spectrumKxKyZ

			else

			[nx,nky,nz]=size(gene_data);
			% extend to whole ky by imposingreality condition
			ny=2*nky-1;
			if ny~=1
			spectrumXKyZ=zeros(nx,ny,nz);
			spectrumXKyZ(:,1:nky,:)=gene_data(:,:,:);
			spectrumXKyZ(1,(nky+1):(ny),:)=conj(gene_data(1,nky:-1:2,:));
			spectrumXKyZ(2:nx,(nky+1):(ny),:)=conj(gene_data(2:1:nx,nky:-1:2,:));
			else
			%pad with zeros to interpolate on fine scale
			ny=50;
			spectrumXKyZ=zeros(nx,ny,nz);
			spectrumXKyZ(:,2,:)=gene_data(:,:,:);

			end
			output=ny*ifft(spectrumXKyZ,[],2,'symmetric');
			clear spectrumK=XKyZ
			end