

biplot {mva}                                 R Documentation

_B_i_p_l_o_t _o_f _M_u_l_t_i_v_a_r_i_a_t_e _D_a_t_a

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

     Plot a biplot on the current graphics device.

_U_s_a_g_e_:

     biplot(x, ...)

     biplot.default(x, y, var.axes = TRUE, col, cex = rep(par("cex"), 2),
                    xlabs = NULL, ylabs = NULL, expand = 1,
                    xlim  = NULL, ylim  = NULL, arrow.len = 0.1, ...)

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

       x: The `biplot', a fitted object. For
          `biplot.default', the first set of points (a two-
          column matrix), usually associated with observa-
          tions.

       y: The second set of points (a two-column matrix),
          usually associated with variables.

var.axes: If `TRUE' the second set of points have arrows
          representing them as (unscaled) axes.

     col: A vector of length 2 giving the colours for the
          first and second set of points respectively (and
          the corresponding axes). If a single colour is
          specified it will be used for both sets.

     cex: The character expansion factor used for labelling
          the points. The labels can be of different sizes
          for the two sets by supplying a vector of length
          two.

   xlabs: A vector of character strings to label the first
          set of points: the default is to use the row dim-
          name of `x', or `1:n' is the dimname is `NULL'.

   ylabs: A vector of character strings to label the second
          set of points: the default is to use the row dim-
          name of `y', or `1:n' is the dimname is `NULL'.

  expand: An expansion factor to apply when plotting the
          second set of points relative to the first. This
          can be used to get the two sets on to a physically
          comparable scale.

arrow.len: The length of the arrow heads on the axes plotted
          in `var.axes' is true. The arrow head can be sup-
          pressed by `arrow.len = 0'.

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

     A biplot is plot which aims to represent both the
     observations and variables of a matrix of multivariate
     data on the same plot. There are many variations on
     biplots (see the references) and perhaps the most
     widely used one is implemented by `biplot.princomp'.
     The function `biplot.default' merely provides the
     underlying code to plot two sets of variables on the
     same figure.

     Graphical parameters can also be given to `biplot'.

_S_i_d_e _E_f_f_e_c_t_s_:

     a plot is produced on the current graphics device.

_A_u_t_h_o_r_(_s_)_:

     B.D. Ripley

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

     K. R. Gabriel (1971).  The biplot graphical display of
     matrices with application to principal component analy-
     sis. Biometrika 58, 453-467.

     J.C. Gower and D. J. Hand (1996). Biplots. Chapman &
     Hall.

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

     `biplot.princomp', also for examples.

