invalid                package:gtools                R Documentation

_T_e_s_t _i_f _a _v_a_l_u_e _i_s _m_i_s_s_i_n_g, _e_m_p_t_y, _o_r _c_o_n_t_a_i_n_s _o_n_l_y _N_A _o_r _N_U_L_L _v_a_l_u_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     Test if a value is missing, empty, or contains only NA or NULL
     values.

_U_s_a_g_e:

     invalid(x)

_A_r_g_u_m_e_n_t_s:

       x: value to be tested

_V_a_l_u_e:

     Logical value.

_A_u_t_h_o_r(_s):

     Gregory R. Warnes warnes@bst.rochester.edu

_S_e_e _A_l_s_o:

     'missing', 'is.na', 'is.null'

_E_x_a_m_p_l_e_s:

     invalid(NA)
     invalid()
     invalid(c(NA,NA,NULL,NA))

     invalid(list(a=1,b=NULL))

     # example use in a function
     myplot <- function(x,y) {
                     if(invalid(y)) {
                             y <- x
                             x <- 1:length(y)
                     }
                     plot(x,y)
             }
     myplot(1:10)
     myplot(1:10,NA)