function WriteArray(array, filename)
%WRITEARRAY Writes an array to a file.
%   WriteArray(array, filename) writes array to a file with the name "filename"
%
%   The first four bytes (an integer) in the file indicate the number of dimensions of the array.
%   The size of the array along each of the dimensions are then written as four bytes each (integers),
%   note that the size along each of the dimensions must remain constant
%   The rest of the file contains the array values (double values)
% 
%   The 64-bit IEEE 754 floating-point "double format" bit layout is used
%   to write the byte representation of double values to the file.
% 
%   All values are written to the file in little endian form.
%
%   If the file already exists, then it will be overwritten.
%
%   See also ReadArray

%   Copyright (C) 2005  Vincent Cheung (vincent@psi.toronto.edu, http://www.psi.toronto.edu/~vincent/)
%   
%   This program is free software; you can redistribute it and/or
%   modify it under the terms of the GNU General Public License
%   as published by the Free Software Foundation; either version 2
%   of the License, or (at your option) any later version.
%   
%   This program is distributed in the hope that it will be useful,
%   but WITHOUT ANY WARRANTY; without even the implied warranty of
%   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%   GNU General Public License for more details.
%
%   $Revision: 1.1 $  $Date: Sept. 17, 2004 $


% open the file to write (create if necessary) and as IEEE floating point with little-endian byte ordering
fid = fopen(filename, 'w', 'l');

sz = size(array);
numDimensions = length(sz);

% write the number of dimensions and the size of the array long each dimension
fwrite(fid, numDimensions, 'int32');
fwrite(fid, sz, 'int32');

% write the array values
fwrite(fid, permute(array, numDimensions:-1:1), 'double');

fclose(fid);