def _det_stat_freq(det_freq, data_freq_sq, data_freq, w, Nc, ulen, mplen):
num_cor = np.multiply(det_freq, data_freq)  <EOL>den_cor = np.multiply(w, data_freq_sq)  <EOL>num_ifft = np.real(np.fft.irfft(num_cor))[:, ulen-<NUM_LIT:1>:mplen:Nc]<EOL>denominator = np.real(np.fft.irfft(den_cor))[ulen-<NUM_LIT:1>:mplen:Nc]<EOL>result = np.sum(np.square(num_ifft), axis=<NUM_LIT:0>) / denominator<EOL>return result<EOL>
Compute detection statistic in the frequency domain

:type det_freq: numpy.ndarray
:param det_freq: detector in freq domain
:type data_freq_sq: numpy.ndarray
:param data_freq_sq: squared data in freq domain
:type data_freq: numpy.ndarray
:param data_freq: data in freq domain
:type w: numpy.ndarray
:param w: boxcar in freq domain
:type Nc: int
:param Nc: number of channels in data stream
:type ulen: int
:param ulen: length of detector
:type mplen: int
:param mplen: length of data

:return: Array of detection statistics
:rtype: numpy.ndarray