nndistF               package:splancs               R Documentation

_N_e_a_r_e_s_t _n_e_i_g_h_b_o_u_r _d_i_s_t_a_n_c_e_s _a_s _u_s_e_d _b_y _F_h_a_t()

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

     Calculate nearest neighbour distances as used by  'Fhat()'

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

     nndistF(pts1,pts2)

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

    pts1: A points data set 

    pts2: A points data set 

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

     The set of distances from each of the points in 'pts2' to the
     nearest point in 'pts1' is returned as a vector.

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

     Rowlingson, B. and Diggle, P. 1993 Splancs: spatial point pattern
     analysis code in S-Plus.  Computers and Geosciences, 19, 627-655;
     the original sources can be accessed at: <URL:
     http://www.maths.lancs.ac.uk/~rowlings/Splancs/>. See also Bivand,
     R. and Gebhardt, A. 2000 Implementing functions for spatial
     statistical analysis using the R language. Journal of Geographical
     Systems, 2, 307-317.

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

     'nndistG', 'Fhat', 'Ghat', 'Fzero'

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

     data(uganda)
     boxplot(nndistF(as.points(uganda), as.points(csr(uganda$poly, length(uganda$x)))))
     plot(ecdf(nndistF(as.points(uganda), 
     as.points(csr(uganda$poly, length(uganda$x))))),
     main="Fhat ecdf Uganda volcano data")

