function writeSSRL(immigrant)
%WRITESSRL  save struct data in SSRL binary format and
%           allow MVIEW, MCALIB, MAVE to read
% 
% The input struct data should contain the following fields
%        froot: char array (the root name of the data file)
%         fext: char array (the extension of the data file)
%     beamline: char array (beamline infomation)
%     comments: cell array {6x1} (user comments)
%      recTime: char array (data recording time)
%       labels: cell array {Ncolx1} (labels for each columns)
%      offsets: double array [Ncolx1] (offset for each channels)
%         data: double array [NcolxNpts] (data)
%
% The converted file has a prefix of 'ssrl_' to the original file name
% and can be read by MVIEW, MCALIB, and MAVE.
% 
%*************
% SSRL format
%*************
% 1. 800 bytes = 40 bytes (title MUST start with 'SSRL -') '\n' '0'
%              + 40 bytes (recording date:time) '\n' '0'
%              + 40 bytes (scaler_file) '\n' '0'
%              + 40 bytes (region_file) '\n' '0'
%              + 80 bytes (mirror_info) '\n' '0'
%              + 40 bytes (mirror param) '\n' '0'
%              + 80 bytes x 6 (User comments) '\n' '0'
%
% 2. NCOL*4 bytes (offsets)
%    NCOL*4 bytes (weights)
%
% 3. NCOL*20 bytes (labels for each column)
%
% 4. 4 bytes integer (npts)
%
% 5. mysterious 12 bytes starting w/ char(8),char(0), char(1), char(0)
%    probably it's not important.
%
% 6. NCOL*NPTS*4 bytes (data)
%
%
% Tsu-Chien Weng, 2002-07-24
% Copyleft(c), by the Penner-Hahn research group

% 2004-12-01: add truncateOrFillBlanks() to clean up the codes

fname=['ssrl_' immigrant.froot '.' immigrant.fext];
fid=fopen(fname,'w','vaxd');

[numDataColumns,numDataPoints]=size(immigrant.data);
% char([10 0])=['\n', '0']

% Hallelujah ...
% Tricks: 'SSRL - EXAFS Data Collector 1.3 ';
% 1. 800 bytes of char (headers)
fwrite(fid,[truncateOrFillBlanks('SSRL - EXAFS Data Collector 1.3 ',38), 10 0],'char'); 
fwrite(fid,[truncateOrFillBlanks(immigrant.recTime,38), 10 0],'char');
fwrite(fid,[truncateOrFillBlanks(['PTS: ' num2str(numDataPoints) ' COLS: ' num2str(numDataColumns)],38), 10 0],'char');
fwrite(fid,[truncateOrFillBlanks('UNKNOWN.DET',38), 10 0],'char');
fwrite(fid,[truncateOrFillBlanks('UNKNOWN.RGN',38), 10 0],'char');
fwrite(fid,[truncateOrFillBlanks(immigrant.beamline,78), 10 0],'char');
fwrite(fid,[truncateOrFillBlanks(' ',38), 10 0],'char');
for n=1:6,
    fwrite(fid,[truncateOrFillBlanks(immigrant.comments{n},78), 10 0], 'char');
end

% 2. NCOL*8 bytes of float (channel offsets and weightings)
fwrite(fid,immigrant.offsets,'float');
fwrite(fid,ones(numDataColumns,1),'float');

% 3. NCOL*20 bytes of char (column labels)
for n=1:length(immigrant.labels)
    fwrite(fid,[truncateOrFillBlanks(immigrant.labels{n},18), 10 0],'char');
end

% 4. 4 bytes of integer (numbers of energy points)
fwrite(fid,numDataPoints,'int');

% 5. 12 bytes of mysterious char
fwrite(fid,[8 0 1 0 33 71 24 40 -117 68 11 0],'char');

% 6. NCOL*NPTS*4 bytes of floats (data)
fwrite(fid,immigrant.data,'float');

fclose(fid);

return


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function textString=truncateOrFillBlanks(textString,maxLengthOfString)

lengthOfString=length(textString);
if lengthOfString > maxLengthOfString,
    textString=textString(1:maxLengthOfString);
else
    textString=[textString repmat(' ',1,maxLengthOfString-lengthOfString)];
end

return