# ModelThetaCalculator¶

class gammapy.image.models.ModelThetaCalculator(source, psf, fov, binsz, call2d=False)[source]

Compute containment radius for given radially symmetric source and psf as well as desired containment fraction.

Uses 2D images for the computation. Slow but simple, so useful to check more complicated methods.

Source and PSF must be callable and return dP/dtheta (TODO: or dP/dtheta^2?)

fov = field of view (deg) binsz = bin size (deg)

The source is supposed to be contained in the FOV even after PSF convolution.

Methods Summary

 containment_fraction(theta) Compute containment fraction for a given theta. containment_radius(containment_fraction) Compute theta for a given containment fraction.

Methods Documentation

containment_fraction(theta)

Compute containment fraction for a given theta.

containment_radius(containment_fraction)

Compute theta for a given containment fraction.