isValid.ggobi             package:Rggobi             R Documentation

_D_e_t_e_r_m_i_n_e_s _w_h_e_t_h_e_r _a _r_e_f_e_r_e_n_c_e _t_o _a_n _i_n_t_e_r_n_a_l _g_g_o_b_i _o_b_j_e_c_t _i_s _v_a_l_i_d

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

     One can create multiple, independent ggobi instances within a
     single R session and one can also remove them either
     programmatically or via the GUI.  To be able to refer to these
     objects which are actually C-level internal objects, one has a
     reference or handle from an S object. Since the C level object can
     be destroyed while the S object still refers to them, this
     function allows one to check whether the internal object to which
     S 'ggobi' object refers is still in existence.

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

     isValid.ggobi(.gobi)

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

   .gobi: an object of class 'ggobi' which refers to an internal ggobi
          instance.

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

     A logical value with 'TRUE' indicating that the reference
     identifies a real object that currently exists within the ggobi
     engine, or 'FALSE' that the C level object to which the S object
     refers no longer exists.

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

     Duncan Temple Lang

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

     <URL: http://www.ggobi.org>

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

     'ggobi' 'close.ggobi'

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

       g <- ggobi(system.file("data", "flea.xml", package="Rggobi"), args="-noinit")

        # still valid
       isValid.ggobi(g)  

       close(g)

        # no longer valid.
       isValid.ggobi(g)  

