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, ..., method="C")
       pairdist.ppp(X, ..., method="C")
       pairdist.default(X, Y=NULL, ..., method="C")

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

     X,Y: Arguments specifying the locations of a set of points. For
          'pairdist.ppp', the argument 'X' should be a point pattern
          (object of class '"ppp"'). For 'pairdist.default', typically
          'X' and 'Y' would be numeric vectors of equal length.
          Alternatively 'Y' may be omitted and 'X' may be a list with
          two components 'x' and 'y', or a matrix with two columns. 

     ...: Ignored by 'pairdist.ppp' and 'pairdist.default'. 

  method: String specifying which method of calculation to use. Values
          are '"C"' and '"interpreted"'. Usually not specified. 

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

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

     The function 'pairdist' is generic, with a method for point
     patterns (objects of class '"ppp"') and a default method.

     The method for point patterns expects a single point pattern
     argument 'X' and returns the matrix of its pairwise distances.

     The default method expects that 'X' and 'Y' will determine the
     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 list with two components named 'x' and 'y', or a
     matrix or data frame with two columns.

     The argument 'method' is not normally used. It is retained only
     for checking the validity of the software. If 'method =
     "interpreted"' then the distances are computed using interpreted R
     code only. If 'method="C"' (the default) then C code is used. The
     C code is somewhat 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:

     'crossdist', 'nndist', 'Kest'

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

        data(cells)
        d <- pairdist(cells)

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

