function nf2ff = ReadNF2FF(nf2ff)
% function nf2ff = ReadNF2FF(nf2ff)
%
% internal function to read calculated nf2ff data, use CalcNF2FF to read
% existing nf2ff data
%
% See also: CalcNF2FF, CreateNF2FFBox
%
% openEMS matlab interface
% -----------------------
% author: Thorsten Liebig, 2012

file = nf2ff.hdf5;

hdf_mesh = ReadHDF5Mesh(file);

nf2ff.r = double(hdf_mesh.lines{1});
nf2ff.theta = double(hdf_mesh.lines{2});
nf2ff.phi = double(hdf_mesh.lines{3});

% read attributes
nf2ff.freq = ReadHDF5Attribute(file,'/nf2ff','Frequency');
nf2ff.Prad = ReadHDF5Attribute(file,'/nf2ff','Prad');
nf2ff.Dmax = ReadHDF5Attribute(file,'/nf2ff','Dmax');

try
    nf2ff.Eps_r = ReadHDF5Attribute(file,'/nf2ff','Eps_r');
catch
    nf2ff.Eps_r = ones(size(nf2ff.freq));
end
try
    nf2ff.Mue_r = ReadHDF5Attribute(file,'/nf2ff','Mue_r');
catch
    nf2ff.Mue_r = ones(size(nf2ff.freq));
end

if isOctave
    hdf = load( '-hdf5', file );
    for n=1:numel(nf2ff.freq)
        nf2ff.E_theta{n} = double(hdf.nf2ff.E_theta.FD.(['f' int2str(n-1) '_real']) +1i*hdf.nf2ff.E_theta.FD.(['f' int2str(n-1) '_imag']) );
        nf2ff.E_phi{n} = double(hdf.nf2ff.E_phi.FD.(['f' int2str(n-1) '_real']) +1i*hdf.nf2ff.E_phi.FD.(['f' int2str(n-1) '_imag']) );
        nf2ff.E_norm{n} = double(sqrt(abs(nf2ff.E_theta{n}).^2+abs(nf2ff.E_phi{n}).^2));
        nf2ff.P_rad{n} = double(hdf.nf2ff.P_rad.FD.(['f' int2str(n-1)]));
    end
else
    % matlab compatibility to older versions
    if verLessThan('matlab','7.12')
        % read data
        for n=1:numel(nf2ff.freq)
            nf2ff.E_theta{n} = double(hdf5read(file,['/nf2ff/E_theta/FD/f' int2str(n-1) '_real']) + 1i*hdf5read(file,['/nf2ff/E_theta/FD/f' int2str(n-1) '_imag']));
            nf2ff.E_phi{n} = double(hdf5read(file,['/nf2ff/E_phi/FD/f' int2str(n-1) '_real']) + 1i*hdf5read(file,['/nf2ff/E_phi/FD/f' int2str(n-1) '_imag']));
            nf2ff.E_norm{n} = double(sqrt(abs(nf2ff.E_theta{n}).^2+abs(nf2ff.E_phi{n}).^2));
            nf2ff.P_rad{n} = double(hdf5read(file,['/nf2ff/P_rad/FD/f' int2str(n-1)]));
        end
    else
        % read data
        for n=1:numel(nf2ff.freq)
            nf2ff.E_theta{n} = double(h5read(file,['/nf2ff/E_theta/FD/f' int2str(n-1) '_real']) + 1i*h5read(file,['/nf2ff/E_theta/FD/f' int2str(n-1) '_imag']));
            nf2ff.E_phi{n} = double(h5read(file,['/nf2ff/E_phi/FD/f' int2str(n-1) '_real']) + 1i*h5read(file,['/nf2ff/E_phi/FD/f' int2str(n-1) '_imag']));
            nf2ff.E_norm{n} = double(sqrt(abs(nf2ff.E_theta{n}).^2+abs(nf2ff.E_phi{n}).^2));
            nf2ff.P_rad{n} = double(h5read(file,['/nf2ff/P_rad/FD/f' int2str(n-1)]));
        end
    end
end

% Calculation of right- and left-handed circular polarization
% adopted from
% 2012, Tim Pegg <teepegg@gmail.com>

% cleanup (if exist)
nf2ff.E_cprh = [];
nf2ff.E_cplh = [];

% Setup vectors for converting to LHCP and RHCP polarization senses
[THETHA PHI] = ndgrid(nf2ff.theta,nf2ff.phi);
cosphi = cos(PHI);
sinphi = sin(PHI);

for f=1:numel(nf2ff.freq)
    nf2ff.E_cprh{f} = (cosphi+1i*sinphi) .* (nf2ff.E_theta{f}+1i*nf2ff.E_phi{f})/sqrt(2);
    nf2ff.E_cplh{f} = (cosphi-1i*sinphi) .* (nf2ff.E_theta{f}-1i*nf2ff.E_phi{f})/sqrt(2);
end