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## Function: splitup_freq3()

0 float splitup_freq2(float c0, float c90, float *chirp0, float *chirp90, float norm, float* twice_inv_noise, int n, int offset, int p, int* indices, float* stats, float* working,float* htilde)
This routine implements the two-phase statistic test. It returns the value of the statistic as defined in Eq. (). It is algorithmically similar to splitup_freq2(), except that it allows for the case where the phase of the signal is unknown. The arguments are identical to those of splitup_freq2() but the array stats has elements since the signals are complex.

Note: The GRASP library includes two additional functions which are operationally identical to splitup_freq3(), called splitup_freq4() and splitup_freq5(). The last of these is currently the most efficient implementation of the two-phase test. All the arguments of splitup_freq[3-5]() are identical.

The arguments are:

c0: Input. Used in the same way as in splitup_freq2().
c90: Input. Used in the same way as in splitup_freq2(). Note that if templates have unit norm you can set .
chirp0: Input. An array chirp0[0..n-1] containing the FFT of the 0-phase chirp.
chirp90: Input. An array chirp90[0..n-1] containing the FFT of the -phase chirp.
norm: Input. The normalization of the 0-phase chirp.
twice_inv_noise: Input. The array twice_inv_noise[0..n/2] contains , as described previously. The array element twice_inv_noise[0] contains the DC value, and the array element twice_inv_noise[n/2] contains the value at the Nyquist frequency.
n: Input. Defines the lengths of the previous arrays.
offset: Input. The offset of the moment of maximum signal in the filter output.
p: Input. The number of frequency bands for the vetoing test.
indices: Output. An array indices[0..p-1] used for internal storage of the frequency subintervals (see splitup().
stats: Output. An array stats[0..2p-1] containing the real and imaginary parts of the for .
working: Output. An array working[0..n-1] used for internal storage.
htilde: Input. An array htilde[0..n-1] containing the positive frequency part of .
Authors Bruce Allen, ballen@dirac.phys.uwm.edu, and Patrick Brady, patrick@tapir.caltech.edu, and Jolien Creighton jolien@tapir.caltech.edu.