hendrics.pf_upper_limit(*args, **kwargs)[source] [edit on github]

Upper limit on pulsed fraction, given a measured power in the PDS/Z search.

See power_upper_limit and pf_from_ssig. All arguments are the same as amplitude_upper_limit

pmeas: float

The measured value of power

counts: int

The number of counts in the light curve used to calculate the spectrum

Other Parameters
n: int

The number of summed powers to obtain pmeas. It can be multiple harmonics of the PDS, adjacent bins in a PDS summed to collect all the power in a QPO, or the n in Z^2_n

c: float

The confidence value for the probability (e.g. 0.95 = 95%)

fft_corr: bool

Apply a correction for the expected power concentrated in an FFT bin, which is about 0.773 on average (it’s 1 at the center of the bin, 2/pi at the bin edge.

nyq_ratio: float

Ratio of the frequency of this feature with respect to the Nyquist frequency. Important to know when dealing with FFTs, because the FFT response decays between 0 and f_Nyq similarly to the response inside a frequency bin: from 1 at 0 Hz to ~2/pi at f_Nyq


>>> pfup = pf_upper_limit(40, 30000, 1, 0.99)
>>> np.isclose(pfup, 0.13, atol=0.01)