
Since this function will be called by other This function is simply a wrapper around MinimizerĪn important component of a fit is writing a function to be minimized – MinimizerResult – the optimization result for further details. The best-fit values and, whereĪppropriate, estimated uncertainties and correlations, will all beĬontained in the returned MinimizerResult. Squares of the array will be sent to the underlying fitting method,Įffectively doing a least-squares optimization of the return values.Ī common use for args and kws would be to pass in otherĭata needed to calculate the residual, including such things as theĭata array, dependent variable, uncertainties in the data, and otherĭata structures for the model calculation. For the other methods, the return valueĬan either be a scalar or an array. Levenberg-Marquardt algorithm from leastsq(), this returned value mustīe an array, with a length greater than or equal to the number ofįitting variables in the model. The objective function should return the value to be minimized. Object containing the optimized parameter and severalĬhanged in version 0.9.0: Return value changed to MinimizerResult. **fit_kws ( dict, optional) – Options to pass to the minimizer being used.Solvers other than leastsq and least_squares. calc_covar ( bool, optional) – Whether to calculate the covariance matrix (default is True) for.reduce_fcn ( str or callable, optional) – Function to convert a residual array to a scalar value for the scalar.’omit’ : non-finite values are filtered.’propagate’ : the values returned from userfcn are un-altered.Specifies action if userfcn (or a Jacobian) returns NaN scale_covar ( bool, optional) – Whether to automatically scale the covariance matrix (default is True).The iteration number, resid the current residual array, and *argsĪnd **kws as passed to the objective function. Where params will have the current parameter values, iter Have the signature iter_cb(params, iter, resid, *args, **kws), iter_cb ( callable, optional) – Function to be called at each fit iteration.kws ( dict, optional) – Keyword arguments to pass to fcn.args ( tuple, optional) – Positional arguments to pass to fcn.(…, method=’powell’)įor more details on the fitting methods please refer to the In most cases, these methods wrap and use the method of the same ’emcee’: Maximum likelihood via Monte-Carlo Markov Chain.’slsqp’: Sequential Linear Squares Programming.’trust-constr’: trust-region for constrained optimization (SciPy >= 1.1).’trust-krylov’: Newton GLTR trust-region (SciPy >= 1.0).’trust-exact’: nearly exact trust-region (SciPy >= 1.0).’ampgo’: Adaptive Memory Programming for Global Optimization.’differential_evolution’: differential evolution.’least_squares’: Least-Squares minimization, using Trust Region Reflective method.’leastsq’: Levenberg-Marquardt (default).params ( Parameters) – Contains the Parameters for the model.With the scalar methods the objectiveįunction can either return the residuals array or a single scalar Of residuals (difference between model and data) to be minimized Least_squares, the objective function should return an array fcn ( callable) – Objective function to be minimized.Parameters, and several optional arguments. The minimize function takes an objective function to be minimized,Ī dictionary ( Parameters) containing the model Perform a fit of a set of parameters by minimizing an objective (orĬost) function using one of the several available methods. minimize ( fcn, params, method='leastsq', args=None, kws=None, iter_cb=None, scale_covar=True, nan_policy='raise', reduce_fcn=None, calc_covar=True, **fit_kws ) ¶ See Writing a Fitting Function forĭetails on writing the objective function. It takes an objective function (theįunction that calculates the array to be minimized), a Parameters The minimize() function is a wrapper around Minimizer for
