airdist                package:spdep                R Documentation

_M_e_a_s_u_r_e _d_i_s_t_a_n_c_e _f_r_o_m _p_l_o_t

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

     Measure a distance between two points on a plot using 'locator';
     the function checks 'par("plt")' and 'par("usr")' to try to ensure
     that the aspect ratio y/x is 1, that is that the units of
     measurement in both x and y are equivalent.

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

     airdist(ann=FALSE)

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

     ann: annotate the plot with line measured and distance

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

     a list with members: 

    dist: distance measured

  coords: coordinates between which distance is measured

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

     Roger Bivand Roger.Bivand@nhh.no

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

     'locator'

