CRS-class                 package:sp                 R Documentation

_C_l_a_s_s "_C_R_S" _o_f _c_o_o_r_d_i_n_a_t_e _r_e_f_e_r_e_n_c_e _s_y_s_t_e_m _a_r_g_u_m_e_n_t_s

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

     Interface class to the PROJ.4 projection system. The class is
     defined as an empty stub accepting value NA in the sp package. If
     the spproj package is available, then the class will permit
     spatial data to be associated with coordinate reference systems.
     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.

_O_b_j_e_c_t_s _f_r_o_m _t_h_e _C_l_a_s_s:

     Objects can be created by calls of the form 'CRS("projargs")',
     where "projargs" is a valid string of PROJ.4 arguments. The
     initiation function calls the PROJ.4 library to verify the
     argument set against those known in the library, returning error
     messages where necessary. The complete argument set may be
     retrieved by examining the second list element returned by
     'validObject("CRS object")' to see which additional arguments the
     library will use (which assumptions it is making over and above
     submitted arguments). The function 'CRSargs()' can be used to show
     the expanded argument list used by the PROJ.4 library.

_S_l_o_t_s:

     '_p_r_o_j_a_r_g_s': Object of class '"character"': projection arguments 

_M_e_t_h_o_d_s:

     _s_h_o_w 'signature(object = "CRS")': print projection arguments in
          object 

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

     Roger Bivand Roger.Bivand@nhh.no

_R_e_f_e_r_e_n_c_e_s:

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

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

