You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: path_transitivity.m
    path of file: ./repos/CanlabCore/CanlabCore/External/2019_03_03_BCT
    
    the code of the file until where you have to start completion: function T=path_transitivity(W,transform)
% PATH_TRANSITIVITY             Transitivity based on shortest paths
%
%   T = path_transitivity(W,transform)
%
%   This function computes the density of local detours (triangles) that
%   are available along the shortest-paths between all pairs of nodes.
%
%   Inputs:
%
%       W,
%           unweighted/weighted undirected connection *weight* OR *length*
%           matrix.
%
%
%       transform,
%           If the input matrix is a connection *weight* matrix, specify a
%           transform that map input connection weights to connection
%           lengths. Two transforms are available.
%               'log' -> l_ij = -log(w_ij)
%               'inv' -> l_ij =    1/w_ij
%
%           If the input matrix is a connection *length* matrix, do not
%           specify a transform (or specify an empty transform argument).
%
%
%   Output:

    
function T=path_transitivity(W,transform)
% PATH_TRANSITIVITY             Transitivity based on shortest paths
%
%   T = path_transitivity(W,transform)
%
%   This function computes the density of local detours (triangles) that
%   are available along the shortest-paths between all pairs of nodes.
%
%   Inputs:
%
%       W,
%           unweighted/weighted undirected connection *weight* OR *length*
%           matrix.
%
%
%       transform,
%           If the input matrix is a connection *weight* matrix, specify a
%           transform that map input connection weights to connection
%           lengths. Two transforms are available.
%               'log' -> l_ij = -log(w_ij)
%               'inv' -> l_ij =    1/w_ij
%
%           If the input matrix is a connection *length* matrix, do not
%           specify a transform (or specify an empty transform argument).
%
%
%   Output:
%
%       T,
%           matrix of pairwise path transitivity.
%
%
%   Olaf Sporns, Andrea Avena-Koenigsberger and Joaquin Goñi, IU Bloomington, 2014
%
%   References: Goñi et al (2014) PNAS doi: 10.1073/pnas.131552911
%

if ~exist('transform','var')
    transform = [];
end