# LevMarLSQFitter¶

class astropy.modeling.fitting.LevMarLSQFitter[source] [edit on github]

Bases: object

Levenberg-Marquardt algorithm and least squares statistic.

Notes

The fit_info dictionary contains the values returned by scipy.optimize.leastsq for the most recent fit, including the values from the infodict dictionary it returns. See the scipy.optimize.leastsq documentation for details on the meaning of these values. Note that the x return value is not included (as it is instead the parameter values of the returned model).

Additionally, one additional element of fit_info is computed whenever a model is fit, with the key ‘param_cov’. The corresponding value is the covariance matrix of the parameters as a 2D numpy array. The order of the matrix elements matches the order of the parameters in the fitted model (i.e., the same order as model.param_names).

Attributes

 fit_info (dict) The scipy.optimize.leastsq result for the most recent fit (see notes).

Attributes Summary

 supported_constraints The constraint types supported by this fitter type.

Methods Summary

 __call__(model, x, y[, z, equivalencies]) objective_function(fps, *args) Function to minimize.

Attributes Documentation

supported_constraints = [‘fixed’, ‘tied’, ‘bounds’]

The constraint types supported by this fitter type.

Methods Documentation

__call__(model, x, y, z=None, equivalencies=None, **kwargs)[source] [edit on github]
objective_function(fps, *args)[source] [edit on github]

Function to minimize.

Parameters: fps : list parameters returned by the fitter args : list [model, [weights], [input coordinates]]