

_C_o_r_r_e_l_a_t_i_o_n _a_n_d _C_o_v_a_r_i_a_n_c_e _M_a_t_r_i_c_e_s

     cor(x, y=x, use="all.obs")
     cov(x, y=x, use="all.obs")

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

       x: a matrix or data frame.

       y: a matrix or data frame.

     use: a character string giving the method for handling
          missing observations. This must be one of the
          stringss `"all.obs"', `"complete.obs"' or
          `"pairwise.complete.obs"' (abbreviations are
          acceptable).

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

     The correlation matrix or covariance matrix of the
     columns of `x' and the columns of `y'.

     If `use' has the value `"all.obs"', then the presence
     of missing observations will cause the computation to
     fail.  If `use' has the value `"complete.obs"' then
     missing values are handled by casewise deletion.
     Finally, if `use' has the value
     `"pairwise.complete.obs"' then the correlation between
     each pair of variables is computed using all complete
     pairs of observations on those variables.  This can
     result in correlation matrices which are not positive
     semidefinite.

