pairdist              package:spatstat              R Documentation

_P_a_i_r_w_i_s_e _d_i_s_t_a_n_c_e_s

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

     Computes the matrix of distances between all pairs of points in a
     point pattern.

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

       pairdist(x, y=NULL, method="C")

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

     x,y: Arguments specifying the x and y coordinates of a set of
          points. Typically 'x' and 'y' would be numeric vectors of
          equal length. Alternatively 'y' may be omitted and 'x' may be
          a point pattern (object of class '"ppp"') or a list with two
          components 'x' and 'y', or a matrix with two columns. 

  method: String specifying which method of calculation to use. Values
          are '"C"' and '"interpreted"'. 

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

     This function computes the Euclidean distances between all pairs
     of points, and returns the matrix of distances.

     If 'method = "interpreted"' then the distances are computed using
     interpreted R code only. If 'method="C"' then C code is used. The
     C code is marginally faster.

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

     A square matrix whose '[i,j]' entry is the distance between the
     points numbered 'i' and 'j'.

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

     Pavel Grabarnik pavel.grabar@issp.serpukhov.su and  Adrian
     Baddeley adrian@maths.uwa.edu.au <URL:
     http://www.maths.uwa.edu.au/~adrian/>

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

     'nndist', 'Kest'

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

        x <- runif(100)
        y <- runif(100)
        d <- pairdist(x, y)
        data(cells)
        d <- pairdist(cells)

