Note
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Sine temporal model#
This model parametrises a time model of sinusoidal modulation.
\[F(t) = 1 + amp \cdot \sin(\omega \cdot (t-t_{\rm{ref}}))\]
Example plot#
Here is an example plot of the model:
import numpy as np
from astropy import units as u
from astropy.time import Time
import matplotlib.pyplot as plt
from gammapy.modeling.models import (
Models,
PowerLawSpectralModel,
SineTemporalModel,
SkyModel,
)
time_range = [Time.now(), Time.now() + 16 * u.d]
omega = np.pi / 4.0 * u.rad / u.day
sine_model = SineTemporalModel(
amp=0.5, omega=omega, t_ref=(time_range[0].mjd - 0.1) * u.d
)
sine_model.plot(time_range)
plt.grid(which="both")
YAML representation#
Here is an example YAML file using the model:
model = SkyModel(
spectral_model=PowerLawSpectralModel(),
temporal_model=sine_model,
name="sine-model",
)
models = Models([model])
print(models.to_yaml())
/home/runner/work/gammapy-docs/gammapy-docs/gammapy/.tox/build_docs/lib/python3.9/site-packages/astropy/time/core.py:2408: TimeDeltaMissingUnitWarning: Numerical value without unit or explicit format passed to TimeDelta, assuming days
warn('Numerical value without unit or explicit format passed to'
components:
- name: sine-model
type: SkyModel
spectral:
type: PowerLawSpectralModel
parameters:
- name: index
value: 2.0
- name: amplitude
value: 1.0e-12
unit: cm-2 s-1 TeV-1
- name: reference
value: 1.0
unit: TeV
temporal:
type: SineTemporalModel
parameters:
- name: amp
value: 0.5
- name: omega
value: 0.7853981633974483
unit: d-1 rad
- name: t_ref
value: 59893.664977519125
unit: d