Note

You are not reading the most up to date version of Gammapy documentation.
Access the latest stable version v1.3 or the list of Gammapy releases.

Constant Spatial Model

This model is a spatially constant model.

Example plot

Here is an example plot of the model:

from gammapy.maps import WcsGeom
from gammapy.modeling.models import (
    ConstantSpatialModel,
    Models,
    PowerLawSpectralModel,
    SkyModel,
)

geom = WcsGeom.create(npix=(100, 100), binsz=0.1)
model = ConstantSpatialModel(value="42 sr-1")
model.plot(geom=geom, add_cbar=True)

YAML representation

Here is an example YAML file using the model:

pwl = PowerLawSpectralModel()
constant = ConstantSpatialModel()

model = SkyModel(spectral_model=pwl, spatial_model=constant, name="pwl-constant-model")
models = Models([model])

print(models.to_yaml())

Out:

components:
-   name: pwl-constant-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
            frozen: true
    spatial:
        type: ConstantSpatialModel
        parameters:
        -   name: value
            value: 1.0
            unit: sr-1
            frozen: true