project                package:rgdal                R Documentation

_P_r_o_j_e_c_t_i_o_n _o_f _c_o_o_r_d_i_n_a_t_e _m_a_t_r_i_c_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     Interface to the PROJ.4 library of projection functions for
     geographical position data, no datum transformation possible. Use
     'transform()' for extended support.

_U_s_a_g_e:

     project(xy, proj, inv = FALSE)

_A_r_g_u_m_e_n_t_s:

      xy: 2-column matrix of coordinates 

    proj: character string of projection arguments; the arguments must
          be entered exactly as in the PROJ.4 documentation, in
          particular there cannot be any white space in +<arg>=<value>
          strings, and successive such strings can only be separated by
          blanks. 

     inv: default FALSE, if TRUE inverse projection to geographical
          coordinates 

_D_e_t_a_i_l_s:

     Full details of projection arguments available from website below,
     and examples in file "epsg" in the data directory installed with
     PROJ.4.

_V_a_l_u_e:

     A two column matrix with projected coordinates.

_N_o_t_e:

     The locations of Hawaii and Alaska in the data source are (putting
     it mildly) arbitrary, please avoid airlines using these positions.

_A_u_t_h_o_r(_s):

     Barry Rowlingson, Roger Bivand Roger.Bivand@nhh.no

_R_e_f_e_r_e_n_c_e_s:

     <URL: http://www.remotesensing.org/proj/>

_S_e_e _A_l_s_o:

     'CRS-class', 'spTransform-methods'

_E_x_a_m_p_l_e_s:

     data(state)
     res <- project(cbind(state.center$x, state.center$y), "+proj=lcc +lat_1=48 +lat_2=33 +lon_0=-100")
     res1 <- project(res, "+proj=lcc +lat_1=48 +lat_2=33 +lon_0=-100", inv=TRUE)
     summary(res1 - cbind(state.center$x, state.center$y))
     plot(cbind(state.center$x, state.center$y), asp=1, type="n")
     text(cbind(state.center$x, state.center$y), state.abb)
     plot(res, asp=1, type="n")
     text(res, state.abb)

