aRTlayer                 package:aRT                 R Documentation

_C_l_a_s_s _a_R_T_l_a_y_e_r

_D_e_s_c_r_i_p_t_i_o_n:

     Class that represents a layer of information in the database. It
     can insert geometries into the database, process them and
     create/open 'aRTtable', 'aRTtheme'  and 'aRTquerier' objects.
     TerraLib layers can stores various geometries in a layer, but in
     aRT, for simplify, each layer stores only one type of geometry.

_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 'new("aRTlayer",
     aRTdb, layername, proj)'. Examples:
      'obj = new("aRTlayer", aRTdb, layername, create=T)'
      'obj = new("aRTlayer",db,l="llatlong",proj="+proj=latlong
     +datum=NAD83",c=T)'

     To avoid creating objects this way, there are two functions of
     class 'aRTdb': 'createLayer' and 'openLayer'.

_A_r_g_u_m_e_n_t_s:

     _a_R_T_d_b Object of aRTdb class.

     _l_a_y_e_r_n_a_m_e Name of the layer.

     _p_r_o_j Projection in proj.4 format. Some projections are not
          supported by TerraLib.

     _c_r_e_a_t_e Can the layer be created if it does not exist?

_E_x_t_e_n_d_s:

     Class 'aRTcomponent', directly.

_M_e_t_h_o_d_s:

     _a_d_d_L_i_n_e_s: Insert lines in the layer.

     _a_d_d_P_o_i_n_t_s: Insert points in the layer.

     _a_d_d_P_o_l_y_g_o_n_s: Insert polygons (rings) in the layer.

     _c_r_e_a_t_e_T_h_e_m_e: Create a new theme and returns it.

     _g_e_t_A_t_t_r_i_b_u_t_e_s: Return the stored attributes.

     _g_e_t_G_e_o_m_e_t_r_y: Return the geometries stored in the layer.

     _g_e_t_M_e_t_r_i_c: Return a metric operations (buffer, length, area,
          convex hull).

     _g_e_t_N_N: Nearest Neighbors (not implemented yet).

     _g_e_t_R_e_l_a_t_i_o_n: Look for spatial relations as contains, crosses,
          touches.

     _g_e_t_S_e_t_M_e_t_r_i_c: Calculate a set operation (union, difference,
          intersection, xor).

     _o_p_e_n_T_h_e_m_e: Open an existent theme.

     _p_l_o_t: Plots the data.

     _s_h_o_w_T_a_b_l_e_s: Show all information tables in the layer.

_A_u_t_h_o_r(_s):

     Marcos Aurelio Carrero, Pedro Ribeiro de Andrade Neto

_S_e_e _A_l_s_o:

     See 'aRTlayer-METHOD' for a method of this class or
     'CLASSNAME-class' for links to other classes. Package 'spproj' for
     conversion of projections.

