compute_fvar¶
-
gammapy.time.
compute_fvar
(flux, flux_err)[source]¶ Calculate the fractional excess variance.
This method accesses the the
FLUX
andFLUX_ERR
columns from the lightcurve data.The fractional excess variance Fvar, an intrinsic variability estimator, is given by
Fvar=√S2−¯σ2ˉx2.It is the excess variance after accounting for the measurement errors on the light curve σ. S is the variance.
- Parameters
- Returns
- fvar, fvar_err
ndarray
Fractional excess variance.
- fvar, fvar_err
References
- Vaughan2003
“On characterizing the variability properties of X-ray light curves from active galaxies”, Vaughan et al. (2003) https://ui.adsabs.harvard.edu/abs/2003MNRAS.345.1271V