function save_binary( filename, matrix, row_labels, col_headers, name )
% save_binary( FILENAME, MATRIX, ROW_LABELS, COL_HEADERS, NAME )
%
%	Saves data matrix in a binary format.
%
%	FILENAME:		String containing the filename to write.
%	MATRIX:			n-by-m data matrix.
%	ROW_LABELS:		n-by-1 cell array containing row labels.
%	COL_HEADERS:		m-by-1 cell array containing column headers.
%	NAME:			Description string (ie. the upper-left element in data text-files).
%

% WARNING: No error checking is performed for clarity.


	% Opens the file for writting in the desired format.
	machineformat = ['ieee-le'];
	fid = fopen(filename, 'w', machineformat, 'ISO-8859-15');


	% Size of data matrix.
	[ n m ] = size(matrix);


	% Number of rows: a 32-bits signed integer.
	fwrite( fid, n, 'int32', machineformat );


	% Number of columns: a 32-bits signed integer.
	fwrite( fid, m, 'int32', machineformat );


	% Data matrix: n-by-m 64-bits floating-point values.
	% NOTE: data matrix is transposed before calling fwrite()
	%		in order to save it in row-major format.
	fwrite( fid, matrix', 'real*8', machineformat );


	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	% Optionally, saves row labels, column headers, and name (as plain-text) %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

	% Closes file and returns if there is neither labels nor name.
	if ( (length(col_headers) == 0) && (length(row_labels) == 0) && (length(name) == 0) )
		fclose(fid);
		return;
	end;


	% Row labels (tab-separated).
	if ( length(row_labels) > 0 )
		len = length( row_labels{1} );
		fprintf(fid,'%s',row_labels{1});
		for i=2:n
			len = length( row_labels{i} );
			fprintf(fid,'\t%s',row_labels{i});
		end

	end


	% A newline character.
	fprintf(fid,'\n');


	% Column headers (tab-separated).
	if ( length(col_headers) > 0 )
		len = length( col_headers{1} );
		fprintf(fid,'%s',col_headers{1};
		for i=2:m
			len = length( col_headers{i} );
			fprintf(fid,'\t%s',col_headers{i};
		end
	end


	% A newline character.
	fprintf(fid,'\n');


	% Name: description string (upper-left field in data text files)
	if ( length(name) > 0 )
		fprintf(fid,'%s\n',name);
	end

	fclose(fid);