get_profilemodel

get_profilemodel#

get_profilemodel(name, position=(0, 0), normalized=True, **kwargs)[source]#

Get a 2D profile model from astropy.modeling.functional_models.

Parameters:

  • name (str) –

    Name of the 2D astropy model. Shortcuts:

    • "airy", "airydisk": "AiryDisk2D"

    • "gaussian", "gauss", "normal": "Gaussian2D"

    • "moffat": "Moffat2D"

    • "sersic": "Sersic2D"

    • "ricker", "mexican", "mexicanhat": "RickerWavelet2D"

    • "lorentz": "Lorentz2D"

  • position (tuple of float, optional) – Location (x, y) of the centroid. Default is (0, 0).

  • normalized (bool, optional) – If True, set the model amplitude such that the profile integrates to 1. Only implemented for AiryDisk2D and Gaussian2D. Default is True.

  • **kwargs –

    Additional arguments passed to the astropy model initializer, see https://docs.astropy.org/en/latest/modeling/predef_models2D.html. Model defaults are amplitude=1 and:

    • AiryDisk2D: radius=1

    • Gaussian2D: x_stddev=None, y_stddev=None, theta=None, cov_matrix=None. For convenience, sigma (or radius) can be given to set both x_stddev and y_stddev.

    • Moffat2D: gamma=1, alpha=1

    • Sersic2D: r_eff=1, n=4, ellip=0, theta=0.0

    • RickerWavelet2D: sigma=1

    • Lorentz2D: fwhm=1

Returns:

astropy.modeling.Fittable2DModel – The requested astropy model with its parameters set; call it as model(x, y).

Raises:

ValueError – If normalized is True for a model other than AiryDisk2D or Gaussian2D.

Examples

>>> sigmas = 2  # or array of shape (M, 1, 1)
>>> airy = get_profilemodel("airy", position=(0.4, 1.2), radius=sigmas)
>>> xx = np.r_[-7:7:50j]
>>> yy = np.r_[-7:7:49j]  # different dim for example
>>> airy(xx[None, :], yy[:, None]).shape  # (M, 49, 50) for M radii
(49, 50)