gtrans                  package:sna                  R Documentation

_C_o_m_p_u_t_e _t_h_e _T_r_a_n_s_i_t_i_v_i_t_y _o_f _a_n _I_n_p_u_t _G_r_a_p_h _o_r _G_r_a_p_h _S_t_a_c_k

_D_e_s_c_r_i_p_t_i_o_n:

     'gtrans' returns the transitivity of the elements of 'dat'
     selected by 'g', using the definition of 'measure'.  Triads
     involving missing values are omitted from the analysis.

_U_s_a_g_e:

     gtrans(dat, g=NULL, diag=FALSE, mode="digraph", measure = c("weak", 
         "strong", "weakcensus", "strongcensus"))

_A_r_g_u_m_e_n_t_s:

     dat: A graph or graph stack 

       g: A vector indicating the graphs which are to be analyzed; by
          default, all graphs are analyzed 

    diag: A boolean indicating whether or not diagonal entries (loops)
          are to be taken as valid data 

    mode: '"digraph"' if directed triads are sought, or else '"graph"' 

 measure: One of '"weak"' (default), '"strong"', '"weakcensus"', or
          '"strongcensus"' 

_D_e_t_a_i_l_s:

     Transitivity is a triadic, algebraic structural constraint.  In
     its weak form, the transitive constraint corresponds to a->b->c =>
     a->c.  In the corresponding strong form, the constraint is a->b->c
     <=> a->c.  (Note that the weak form is that most commonly
     employed.)  Where 'measure=="weak"', the fraction of potentially
     intransitive triads obeying the weak condition is returned.  With
     the 'measure=="weakcensus"' setting, by contrast, the total
     _number_ of transitive triads is computed.  The 'strong' versions
     of the measures are similar to the above, save in that the set of
     all triads is considered (since all are ``at risk'' for
     intransitivity).

_V_a_l_u_e:

     A vector of transitivity scores

_N_o_t_e:

     In version 0.3, the strong form was the default (and only) option
     for 'gtrans'.

_A_u_t_h_o_r(_s):

     Carter T. Butts buttsc@uci.edu

_R_e_f_e_r_e_n_c_e_s:

     Holland, P.W., and Leinhardt, S.  (1972).  ``Some Evidence on the
     Transitivity of Positive Interpersonal Sentiment.'' _American
     Journal of Sociology,_ 72, 1205-1209.

     Wasserman, S., and Faust, K.  (1994).  _Social Network Analysis:
     Methods and Applications_.  Cambridge: Cambridge University Press.

_S_e_e _A_l_s_o:

     'triad.classify', 'cugtest'

_E_x_a_m_p_l_e_s:

     #Draw some random graphs
     g<-rgraph(5,10)

     #Find transitivity scores
     gtrans(g)

