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- LinearLSQFitter

# LinearLSQFitter

class astropy.modeling.fitting.LinearLSQFitter(calc_uncertainties=False)

  Bases: `object`

  A class performing a linear least square fitting. Uses `numpy.linalg.lstsq` to do the fitting. Given a model and data, fits the model to the data and changes the model’s parameters. Keeps a dictionary of auxiliary fitting information. Notes —– Note that currently LinearLSQFitter does not support compound models.

  Attributes Summary

  `supported_constraints` |
  `supports_masked_input` |

  Methods Summary

  `__call__`(model, x, y[, z, weights, rcond]) | Fit data to this model.

  Attributes Documentation

  supported_constraints = ['fixed']
  supports_masked_input = True

  Methods Documentation

  __call__(model, x, y, z=None, weights=None, rcond=None)

    Fit data to this model.

    Parameters:
      model `FittableModel`

        model to fit to x, y, z

      x `array`

        Input coordinates

      y numpy:array_like

        Input coordinates

      z numpy:array_like, optional

        Input coordinates. If the dependent (`y` or `z`) coordinate values are provided as a `numpy.ma.MaskedArray`, any masked points are ignored when fitting. Note that model set fitting is significantly slower when there are masked points (not just an empty mask), as the matrix equation has to be solved for each model separately when their coordinate grids differ.

      weights `array`, optional

        Weights for fitting. For data with Gaussian uncertainties, the weights should be 1/sigma.

      rcond `python:float`, optional

        Cut-off ratio for small singular values of `a`. Singular values are set to zero if they are smaller than `rcond` times the largest singular value of `a`.

      equivalencies `python:list` or `python:None`, optional, keyword-only

        List of additional equivalencies that are should be applied in case x, y and/or z have units. Default is None.

    Returns:
      model_copy `FittableModel`

        a copy of the input model with parameters set by the fitter