kernrat               package:splancs               R Documentation

_R_a_t_i_o _o_f _t_w_o _k_e_r_n_e_l _s_m_o_o_t_h_i_n_g_s

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

     Return the ratio of two kernel smoothings

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

     kernrat(pts1,pts2,poly,h1,h2,nx=20,ny=20,kernel='quartic')

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

pts1,pts2: Point data sets 

    poly: A polygon data set 

   h1,h2: The kernel width parameters, `h1' for `pts1', and `h2' for
          `pts2' 

      nx: Number of points along the x-axis of the returned grid. 

      ny: Number of points along the y-axis of the returned grid. 

  kernel: Type of kernel function to use. Currently only the quartic
          kernel is implemented. 

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

     A list with the following components: 

       x: List of x-coordinates at which the kernel function has been
          evaluated.

       y: List of y-coordinates at which the kernel function has been
          evaluated.

       z: A matrix of dimension `nx' by `ny' containing the ratio of
          the kernel functions.

       h: A vector of length 2 containing `h1' and `h2'

  kernel: a character string containing the kernel name.

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

     Berman M. and Diggle P.J. (1989) Estimating Weighted Integrals of
     the Second-Order Intensity of Spatial Point Patterns. J. R.
     Statist Soc B51 81-92; 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:

     `kernel2d', `mse2d'

