arcdist                package:ssBase                R Documentation

_A_r_c _D_i_s_t_a_n_c_e _B_e_t_w_e_e_n _E_p_i_c_e_n_t_r_a_l _L_o_c_a_t_i_o_n_s

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

     Calculates the arc-distance on the spherical surface between one
     epicentral location and a set of other locations.

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

     arcdist(point1, points2, radius = 6371)

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

  point1: a vector containing the longitude and latitude of the
          "central" point.

 points2: a matrix containing the other points, one in each row. The
          first column contains the longitudes and the second contains
          the latitudes.

  radius: the radius of the sphere, default is 6371.

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

     A vector of arclengths the same length as number of rows in
     'points2'.

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

     David Harte, 2002

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

     'epi.circle', 'epicentres'

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

     x <- arcdist(c(174, -42), cbind(c(174, 174, 175), c(-42, -43, -43)))
     print(x)

