is.na-methods             package:Matrix             R Documentation

_i_s._n_a() _M_e_t_h_o_d_s _f_o_r '_M_a_t_r_i_x' _O_b_j_e_c_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     Methods for function 'is.na()' for all Matrices (objects extending
     the 'Matrix' class):


     _x = "_d_e_n_s_e_M_a_t_r_i_x" returns a '"nMatrix"' object of same dimension
          as 'x', with TRUE's whenever 'x' was NA.

     _x = "_s_p_a_r_s_e_M_a_t_r_i_x" ditto.

_U_s_a_g_e:

     ## S4 method for signature 'sparseMatrix':
     is.na(x)

_A_r_g_u_m_e_n_t_s:

       x: sparse or dense matrix.

_S_e_e _A_l_s_o:

     'NA', 'is.na'; 'nMatrix', 'denseMatrix', 'sparseMatrix'.

_E_x_a_m_p_l_e_s:

     M <- Matrix(1:6, nrow=4, ncol=3,
            dimnames = list(c("a", "b", "c", "d"), c("A", "B", "C")))
     stopifnot(all(!is.na(M)))
     M[2:3,2] <- NA
     is.na(M)

     A <- spMatrix(10,20, i = c(1,3:8),
                          j = c(2,9,6:10),
                          x = 7 * (1:7))
     stopifnot(all(!is.na(A)))
     A[2,3] <- A[1,2] <- A[5, 5:9] <- NA
     inA <- is.na(A)
     stopifnot(sum(inA) == 1+1+5)

