o
    Eb~)                     @   s~   d Z ddlZddlZddlZddlmZmZm	Z	m
Z
 ddlmZ ddlmZ g Zdd ZG d	d
 d
Z					dddZdS )zTrust-region optimization.    N   )_check_unknown_options_status_messageOptimizeResult_prepare_scalar_function)HessianUpdateStrategy)
FD_METHODSc                    s.   dgd u rd fS  fdd}|fS )Nr   c                    s*   d  d7  < t | g|  R  S )Nr   r   )npcopy)xZwrapper_argsargsfunctionZncalls =/usr/lib/python3/dist-packages/scipy/optimize/_trustregion.pyfunction_wrapper   s   z(_wrap_function.<locals>.function_wrapperr   )r   r   r   r   r   r   _wrap_function   s
   r   c                   @   sj   e Zd ZdZdddZdd Zedd Zed	d
 Zedd Z	dd Z
edd Zdd Zdd ZdS )BaseQuadraticSubproblemaQ  
    Base/abstract class defining the quadratic model for trust-region
    minimization. Child classes must implement the ``solve`` method.

    Values of the objective function, Jacobian and Hessian (if provided) at
    the current iterate ``x`` are evaluated on demand and then stored as
    attributes ``fun``, ``jac``, ``hess``.
    Nc                 C   sF   || _ d | _d | _d | _d | _d | _d | _|| _|| _|| _	|| _
d S N)_x_f_g_h_g_magZ_cauchy_pointZ_newton_point_fun_jac_hess_hessp)selfr   funjachesshesspr   r   r   __init__&   s   
z BaseQuadraticSubproblem.__init__c                 C   s*   | j t| j| dt|| |  S )Ng      ?)r   r	   dotr    r"   r   pr   r   r   __call__3   s   *z BaseQuadraticSubproblem.__call__c                 C      | j du r| | j| _ | j S )z1Value of objective function at current iteration.N)r   r   r   r   r   r   r   r   6      
zBaseQuadraticSubproblem.func                 C   r(   )z=Value of Jacobian of objective function at current iteration.N)r   r   r   r)   r   r   r   r    =   r*   zBaseQuadraticSubproblem.jacc                 C   r(   )z<Value of Hessian of objective function at current iteration.N)r   r   r   r)   r   r   r   r!   D   r*   zBaseQuadraticSubproblem.hessc                 C   s&   | j d ur|  | j|S t| j|S r   )r   r   r	   r$   r!   r%   r   r   r   r"   K   s   
zBaseQuadraticSubproblem.hesspc                 C   s    | j du rtj| j| _ | j S )zAMagnitude of jacobian of objective function at current iteration.N)r   scipylinalgZnormr    r)   r   r   r   jac_magQ   s   
zBaseQuadraticSubproblem.jac_magc                 C   s   t ||}dt || }t |||d  }t|| d| |  }|t|| }| d|  }	d| | }
t|	|
gS )z
        Solve the scalar quadratic equation ||z + t d|| == trust_radius.
        This is like a line-sphere intersection.
        Return the two values of t, sorted from low to high.
              )r	   r$   mathZsqrtZcopysignsorted)r   zdtrust_radiusabcZsqrt_discriminantZauxtatbr   r   r   get_boundaries_intersectionsX   s   	z4BaseQuadraticSubproblem.get_boundaries_intersectionsc                 C   s   t d)Nz9The solve method should be implemented by the child class)NotImplementedError)r   r5   r   r   r   solveo   s   zBaseQuadraticSubproblem.solve)NN)__name__
__module____qualname____doc__r#   r'   propertyr   r    r!   r"   r-   r;   r=   r   r   r   r   r      s    
	



r   r         ?     @@333333?-C6?FTc           "         sf  t | |du rtd|du r|du rtd|du r tdd|	  kr-dk s2td td|dkr:td|dkrBtd	||krJtd
t| }t| ||||d  j}  j}t	|rh j
}nt	|rmn|tv svt|trd} fdd}ntdt||\}}|du rt|d }d}|}|}|r|g}||| |||}d}|j|
kr>z	||\}}W n tjjy   d}Y nyw ||}|| }||| |||}|j|j }|j| }|dkrd}nV|| }|dk r|d9 }n|dkr|rtd| |}||	kr|}|}|r|t| |dur$|t| |d7 }|j|
k r1d}n||kr9d}n|j|
kstd td ddf} |r|dkrWt| |  ntd| |   td|j  td|  td j  td j  td j|d    t||dk||j|j j j j|d  || | d
}!|dur|j
|!d< |r||!d< |!S ) a  
    Minimization of scalar function of one or more variables using a
    trust-region algorithm.

    Options for the trust-region algorithm are:
        initial_trust_radius : float
            Initial trust radius.
        max_trust_radius : float
            Never propose steps that are longer than this value.
        eta : float
            Trust region related acceptance stringency for proposed steps.
        gtol : float
            Gradient norm must be less than `gtol`
            before successful termination.
        maxiter : int
            Maximum number of iterations to perform.
        disp : bool
            If True, print convergence message.
        inexact : bool
            Accuracy to solve subproblems. If True requires less nonlinear
            iterations, but more vector products. Only effective for method
            trust-krylov.

    This function is called by the `minimize` function.
    It is not supposed to be called directly.
    Nz7Jacobian is currently required for trust-region methodsz_Either the Hessian or the Hessian-vector product is currently required for trust-region methodszBA subproblem solving strategy is required for trust-region methodsr   g      ?zinvalid acceptance stringencyz%the max trust radius must be positivez)the initial trust radius must be positivez?the initial trust radius must be less than the max trust radius)r    r!   r   c                    s     | |S r   )r!   r$   )r   r&   r   Zsfr   r   r"      s   z%_minimize_trust_region.<locals>.hessp      r.   g      ?r   successmaxiterz:A bad approximation caused failure to predict improvement.z3A linalg error occurred, such as a non-psd Hessian.z	Warning: z#         Current function value: %fz         Iterations: %dz!         Function evaluations: %dz!         Gradient evaluations: %dz          Hessian evaluations: %d)
r   rJ   statusr   r    nfevZnjevnhevZnitmessager!   allvecs)r   
ValueError	Exceptionr	   ZasarrayZflattenr   r   Zgradcallabler!   r   
isinstancer   r   lenr-   r=   r,   ZLinAlgErrorminappendr
   r   printrM   ZngevrN   r   r    )"r   Zx0r   r    r!   r"   Z
subproblemZinitial_trust_radiusZmax_trust_radiusZetaZgtolrK   ZdispZ
return_allcallbackZinexactZunknown_optionsZnhesspZwarnflagr5   r   rP   mkr&   Zhits_boundaryZpredicted_valueZ
x_proposedZ
m_proposedZactual_reductionZpredicted_reductionZrhoZstatus_messagesresultr   rG   r   _minimize_trust_regiont   s   





9


r]   )r   NNNNrC   rD   rE   rF   NFFNT)rA   r1   Znumpyr	   Zscipy.linalgr+   	_optimizer   r   r   r   Z'scipy.optimize._hessian_update_strategyr   Z(scipy.optimize._differentiable_functionsr   __all__r   r   r]   r   r   r   r   <module>   s     X