
    çgG                     .   d Z ddlZddlmZ g dZ ed           ej        d          dd                        Z ed           ej        d          dd	                        Z ed           ej        d          dd                        Z	dS )zTrophic levels    N)not_implemented_for)trophic_levelstrophic_differencestrophic_incoherence_parameter
undirectedweight)
edge_attrsc                    ddl }t          j        | |          j                                        }|                    |d          }||dk             dd|dk    f         }|||dk             dd|j        f         z  }|j        d         }|                    |          }	 |j	        
                    ||z
            }n.# |j	        j        $ r}	d}
t          j        |
          |	d}	~	ww xY w|                    d          dz   }i }d | j        D             }|D ]}d||<   d | j        D             }t          |          D ]\  }}|                    |          ||<   |S )	a  Compute the trophic levels of nodes.

    The trophic level of a node $i$ is

    .. math::

        s_i = 1 + \frac{1}{k^{in}_i} \sum_{j} a_{ij} s_j

    where $k^{in}_i$ is the in-degree of i

    .. math::

        k^{in}_i = \sum_{j} a_{ij}

    and nodes with $k^{in}_i = 0$ have $s_i = 1$ by convention.

    These are calculated using the method outlined in Levine [1]_.

    Parameters
    ----------
    G : DiGraph
        A directed networkx graph

    Returns
    -------
    nodes : dict
        Dictionary of nodes with trophic level as the value.

    References
    ----------
    .. [1] Stephen Levine (1980) J. theor. Biol. 83, 195-207
    r   Nr      )axiszTrophic levels are only defined for graphs where every node has a path from a basal node (basal nodes are nodes with no incoming edges).c              3   ,   K   | ]\  }}|d k    |V  dS r   N .0node_iddegrees      b/var/www/html/ai-engine/env/lib/python3.11/site-packages/networkx/algorithms/centrality/trophic.py	<genexpr>z!trophic_levels.<locals>.<genexpr>I   s*      OO&6Q;;W;;;;OO    c              3   ,   K   | ]\  }}|d k    |V  dS r   r   r   s      r   r   z!trophic_levels.<locals>.<genexpr>N   s+      RROGVfPQkkkkkkRRr   )numpynxadjacency_matrixTtoarraysumnewaxisshapeeyelinalginvLinAlgErrorNetworkXError	in_degree	enumerateitem)Gr   nparowsumpnninerrmsgylevelszero_node_idsr   nonzero_node_idss                   r   r   r   	   s   F  	Af---/7799A VVAAVF	&A+qqq&A+~&A	F6Q;2:..A 
B
r

A	-IMM!a%  9  - - -) 	
 s##,- 	
1AF POAKOOOM   w SRq{RRR 011 $ $
7&&))wMs   $C C-C((C-c                 r    t          | |          }i }| j        D ]\  }}||         ||         z
  |||f<   |S )as  Compute the trophic differences of the edges of a directed graph.

    The trophic difference $x_ij$ for each edge is defined in Johnson et al.
    [1]_ as:

    .. math::
        x_ij = s_j - s_i

    Where $s_i$ is the trophic level of node $i$.

    Parameters
    ----------
    G : DiGraph
        A directed networkx graph

    Returns
    -------
    diffs : dict
        Dictionary of edges with trophic differences as the value.

    References
    ----------
    .. [1] Samuel Johnson, Virginia Dominguez-Garcia, Luca Donetti, Miguel A.
        Munoz (2014) PNAS "Trophic coherence determines food-web stability"
    r   )r   edges)r)   r   r4   diffsuvs         r   r   r   U   sQ    8 Af---FE . .1q	F1I-q!fLr   Fc                 t   ddl }|rt          | |          }n`t          t          j        |                     }|r*|                                 }|                    |           n| }t          ||          }t          |                    t          |	                                                              S )a+  Compute the trophic incoherence parameter of a graph.

    Trophic coherence is defined as the homogeneity of the distribution of
    trophic distances: the more similar, the more coherent. This is measured by
    the standard deviation of the trophic differences and referred to as the
    trophic incoherence parameter $q$ by [1].

    Parameters
    ----------
    G : DiGraph
        A directed networkx graph

    cannibalism: Boolean
        If set to False, self edges are not considered in the calculation

    Returns
    -------
    trophic_incoherence_parameter : float
        The trophic coherence of a graph

    References
    ----------
    .. [1] Samuel Johnson, Virginia Dominguez-Garcia, Luca Donetti, Miguel A.
        Munoz (2014) PNAS "Trophic coherence determines food-web stability"
    r   Nr   )
r   r   listr   selfloop_edgescopyremove_edges_fromfloatstdvalues)r)   r   cannibalismr*   r9   
self_loopsG_2s          r   r   r   x   s    8  8#Af555 "+A..//
 	&&((C!!*---- C#C777U\\^^,,--...r   r   )r   F)
__doc__networkxr   networkx.utilsr   __all___dispatchabler   r   r   r   r   r   <module>rL      s         . . . . . .
T
T
T \""X&&&G G G '& #"GT \""X&&&   '& #"B \""X&&&)/ )/ )/ '& #")/ )/ )/r   