function y = CPR_L1B_rdr(filelist,fieldlist)

% CPR L1B HDF-EOS reader 
% 
% VER: BETA 1
%
% INPUT
% filelist is a struct array generated by the dir command
% fieldlist is a cell array with each element matching one of the CPR L1B HDF-EOS fields
%   (omit to select all fields)
% Exception: the 'Sigma-Zero' field is renamed in output as 's0'
%
% OUTPUT
% y is a struct array with as many elements as the number of files in the filelist
% and the (selected) fields from the HDF-EOS file
%
% Example: 
% filelist = dir('*.hdf');
% y = CPR_L1B_rdr(filelist(1:2),{'TAI_start','Latitude','Longitude'});
% 
% will generate
% 
% y = 1x2 struct array with fields:
%    TAI_start
%    Latitude
%    Longitude
% 
% Coefficients and formats
% BETA 0
% 1) Converts all fields into double precision variables
% 2) 'Sigma-Zero' field is renamed in output as 's0'
% BETA 1
% 1 - 2) as in BETA 0
% 3) Applies 0.01 coeff to Sigma-Zero to obtain value in dB
% 4) Applies 1000 coeff to Spacecraft_Altitude to convert km in m


if nargin < 2
    fieldlist = [];
end

for ifile = 1:length(filelist)
    file = filelist(ifile).name;
    
    fileinfo = hdfinfo(file,'eos');
    
    NDataFields = length(fileinfo.Swath.DataFields);
    NGeoFields = length(fileinfo.Swath.GeolocationFields);
    
    if ifile == 1

        y = struct('dummyfield',[]);
        
        for i = 1:NDataFields
            if isempty(fieldlist) | any(strcmp(fieldlist,fileinfo.Swath.DataFields(i).Name))
                if strcmp(fileinfo.Swath.DataFields(i).Name,'Sigma-Zero')
                    out = 's0';
                else
                    out = fileinfo.Swath.DataFields(i).Name;
                end
                y = setfield(y,out,[]);
            end
        end
        
        for i = 1:NGeoFields
            if isempty(fieldlist) | any(strcmp(fieldlist,fileinfo.Swath.GeolocationFields(i).Name))
                y = setfield(y,fileinfo.Swath.GeolocationFields(i).Name,[]);
            end
        end
        
        y = repmat(y,[1,length(filelist)]);
        
        y = rmfield(y,'dummyfield');
        
    end
    
    for i = 1:NDataFields
        if isempty(fieldlist) | any(strcmp(fieldlist,fileinfo.Swath.DataFields(i).Name))
            if strcmp(fileinfo.Swath.DataFields(i).Name,'Sigma-Zero')
                out = 's0';
                coeff = 1/100;
            else
                out = fileinfo.Swath.DataFields(i).Name;
                coeff = 1;
            end
            dummy = hdfread(fileinfo.Filename,fileinfo.Swath.DataFields(i).Name);
            if iscell(dummy), dummy = dummy{1}; end
            dummy = double(dummy) * coeff;
            eval(['y(ifile).' out ' = dummy;'])
        end
    end
    
    for j = 1:NGeoFields
        if isempty(fieldlist) | any(strcmp(fieldlist,fileinfo.Swath.GeolocationFields(j).Name))
            dummy = hdfread(fileinfo.Filename,fileinfo.Swath.GeolocationFields(j).Name);
            if iscell(dummy), dummy = dummy{1}; end
            if strcmp(fileinfo.Swath.GeolocationFields(j).Name,'Spacecraft_altitude')
                coeff = 1000;
            else
                coeff = 1;
            end
            dummy = double(dummy) * coeff;
            eval(['y(ifile).' fileinfo.Swath.GeolocationFields(j).Name ' = dummy;'])
        end
    end
    
end