dudi                  package:ade4                  R Documentation

_D_u_a_l_i_t_y _D_i_a_g_r_a_m

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

     'as.dudi' is called by many functions ('dudi.pca', 'dudi.coa',
     'dudi.acm', ...)  and not directly by the user. It creates duality
     diagrams.

     't.dudi' returns an object of class 'dudi' where the rows are the
     columns and the columns are the rows of the initial dudi. 

     'is.dudi' returns TRUE if the object is of class 'dudi' 

     'redo.dudi' computes again an analysis, eventually changing the
     number of kept axes. Used by other functions.

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

     as.dudi(df, col.w, row.w, scannf, nf, call, type, tol = 1e-07, 
         full = FALSE) 
     print.dudi(x, ...) 
     is.dudi(x) 
     redo.dudi(dudi, newnf = 2) 
     t.dudi(x) 

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

      df: a data frame with n rows and p columns

   col.w: a numeric vector containing the row weights

   row.w: a numeric vector containing the column weights

  scannf: a logical value indicating whether the eigenvalues bar plot
          should be displayed

      nf: if scannf FALSE, an integer indicating the number of kept
          axes

    call: generally 'match.call()'

    type: a string of characters : the returned list will be of class
          'c(type, "dudi")'

     tol: a tolerance threshold for null eigenvalues (a value less than
          tol times the first one is considered as null)

    full: a logical value indicating whether all non null eigenvalues
          should be kept

 x, dudi: objects of class 'dudi'

     ...: further arguments passed to or from other methods

   newnf: an integer indicating the number of kept axes

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

     as.dudi and all the functions that use it return a list with the
     following components : 

     tab: a data frame with n rows and p columns

      cw: row weights, a vector with n components

      lw: column weights, a vector with p components

     eig: eigenvalues, a vector with min(n,p) components

      nf: integer, number of kept axes

      c1: principal axes, data frame with p rows and nf columns

      l1: principal components, data frame with n rows and nf columns

      co: column coordinates, data frame with p rows and nf columns

      li: row coordinates, data frame with n rows and nf columns

    call: original call

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

     Daniel Chessel chessel@biomserv.univ-lyon1.fr

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

     Escoufier, Y. (1987)  The duality diagram  : a means of better
     practical applications  In _Development in numerical ecology_,
     Legendre, P. & Legendre, L. (Eds.)  NATO advanced Institute, 
     Serie G. Springer Verlag, Berlin,  139-156.

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

     data(deug)
     dd1 <- dudi.pca(deug$tab, scannf = FALSE)
     dd1
     t(dd1)
     is.dudi(dd1)
     redo.dudi(dd1,3)

