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:

