pf_upper_limit¶
- 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
andpf_from_ssig
. All arguments are the same asamplitude_upper_limit
- Parameters
- 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
Examples
>>> pfup = pf_upper_limit(40, 30000, 1, 0.99) >>> np.isclose(pfup, 0.13, atol=0.01) True