function data = qifft(data);
% QIFFT Inverse Fourier transform one-sided frequency domain data
%
% QIFFT computes the inverse Fourier transform of one-sided frequency
% domain data produced by QFFT, QCONDITION, and QSCANCONDITION.  The
% frequency domain data are assumed to extend from zero frequency to
% the Nyquist frequency.  As a result the frequency domain data are of
% length N / 2 + 1 while the time domain data are of length N.
%
% usage:
%
% timeDomainData = qifft(frequencyDomainData);
%
%   frequencyDomainData   cell array of one-sided frequency domain data
%
%   timeDomainData        cell array of time domain data
%
% See also QFFT, QCONDITION, and QSCANCONDITION.

% Shourov K. Chatterji
% shourov@ligo.mit.edu

% $Id: qifft.m,v 1.1 2006/10/05 17:00:14 shourov Exp $

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                        process command line arguments                        %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% check for sufficient command line arguments
error(nargchk(1, 1, nargin));

% force cell array of data
if ~iscell(data),
  data = mat2cell(data, size(data, 1), size(data, 2));
end

% force one dimensional cell array
data = data(:);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                       validate command line arguments                        %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% determine number of channels
numberOfChannels = length(data);

% force row vectors
for channelNumber = 1 : numberOfChannels,
  data{channelNumber} = data{channelNumber}(:).';
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                        inverse fast fourier transform                        %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% inverse Fourier transform
for channelNumber = 1 : numberOfChannels,
  data{channelNumber} = real(ifft([data{channelNumber} ...
                        conj(fliplr(data{channelNumber}(2 : end - 1)))]));
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                    return                                    %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% return to calling function
return;