ifourier_GENE.m
21ab15e0edddmaster

ifourier_GENE.m
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			function [ field_r ] = ifourier_GENE( field_c )
			%IFOURIER_FIELD_GENE method of ifourier used in GENE post processing
			% This fourier transform back from the half complex plane to a full real
			% space, in 2 or 3D (dim). Compied from computeFXYZ of GENE for
			% comparison purpose.

			%% Original
			[nky,nx,nz]=size(field_c);
			%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(ny,nx,nz);
			spectrumKxKyZ(1:nky,:,:)=field_c(:,:,:);
			spectrumKxKyZ((nky+1):(ny),1,:)=conj(field_c(nky:-1:2,1,:));
			spectrumKxKyZ((nky+1):(ny),2:nx,:)=conj(field_c(nky:-1:2,nx:-1:2,:));
			else
			%pad with zeros to interpolate on fine scale
			ny=20;
			spectrumKxKyZ=zeros(nx,ny,nz);
			spectrumKxKyZ(:,2,:)=field_c(:,:,:);
			end

			%inverse fft, symmetric as we are using real data
			spectrumXKyZ=nx*ifft(spectrumKxKyZ,[],1);
			field_r=ny*ifft(spectrumXKyZ,[],2,'symmetric');
			clear spectrumKxKyZ

			%% Adapted for HeLaZ old representation
			% [nkx,ny,nz]=size(field_c);
			% %extend to whole ky by imposing reality condition
			% nx=2*nkx-1;
			%
			% %note, we need one extra point which we set to zero for the ifft
			% spectrumKxKyZ=zeros(nx,ny,nz);
			% spectrumKxKyZ(1:nkx,:,:)=field_c(:,:,:);
			% spectrumKxKyZ((nkx+1):(nx),1,:)=conj(field_c(nkx:-1:2,1,:));
			% spectrumKxKyZ((nkx+1):(nx),2:ny,:)=conj(field_c(nkx:-1:2,ny:-1:2,:));
			%
			% %inverse fft, symmetric as we are using real data
			% spectrumXKyZ=nx*ifft(spectrumKxKyZ,[],1);
			% field_r=ny*ifft(spectrumXKyZ,[],2,'symmetric');
			% clear spectrumKxKyZ

			end