Source code for feets.extractors.ext_excess_variance
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2017-2024, Cabral, Juan
# Copyright (c) 2025, QuatroPe; Clariá, Felipe
# License: MIT
# Full Text:
# https://github.com/quatrope/feets/blob/master/LICENSE
# =============================================================================
# DOC
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"""Excess variance extractor."""
# =============================================================================
# IMPORTS
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from light_curve import ExcessVariance as _ExcessVariance
from .light_curve_extractor import LightCurveExtractor
from ..libs import doctools
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# EXTRACTOR CLASS
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[docs]
class ExcessVariance(LightCurveExtractor):
r"""Excess variance extractor.
**ExcessVariance**
Measure of the variability amplitude
.. math::
\frac{\sigma_m^2 - \langle \delta^2 \rangle}{\langle m \rangle^2},
Note that this definition differs from [sanchez2017infrared]_.
Parameters
----------
transform : str or bool or None, optional
Transformer to apply to the feature values. If str, must be one of:
- 'default' - use default transformer for the feature, it same as
giving True. The default for this feature is 'identity'
- 'arcsinh' - Hyperbolic arcsine feature transformer
- 'clipped_lg' - Decimal logarithm of a value clipped to a minimum
value
- 'identity' - Identity feature transformer
- 'lg' - Decimal logarithm feature transformer
- 'ln1p' - :math:`ln(1+x)` feature transformer
- 'sqrt' - Square root feature transformer
If bool, must be True to use default transformer or False to disable.
If None, no transformation is applied.
References
----------
.. [sanchez2017infrared] Sánchez, P., Lira, P., Cartier, R., Pérez, V.,
Miranda, N., Yovaniniz, C., ... & Marchesi, S. (2017).
Near-infrared variability of obscured and unobscured X-ray-selected AGNs
in the COSMOS field. The Astrophysical Journal, 849(2), 110.
"""
features = ["ExcessVariance"]
def __init__(self, transform=None):
self.transform = transform
self._extract = _ExcessVariance(**self.params)
