

Logic {base}                                 R Documentation

_L_o_g_i_c_a_l _O_p_e_r_a_t_o_r_s

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

     These operators act on logical vectors.

_U_s_a_g_e_:

     ! x
     x & y
     x && y
     x | y
     x || y
     xor(x, y)

_D_e_t_a_i_l_s_:

     `!' indicates logical negation (NOT).

     `&' and `&&' indicate logical AND and `|' and `||'
     indicate logical OR.  The shorter form performs elemen-
     twise comparisons in much the same way as arithmetic
     operators.  The longer form evaluates left to right
     examining only the first element of each vector.  Eval-
     uation proceeds only until the result is determined.
     The longer form is appropriate for programming control-
     flow.

     `xor' indicates elementwise exclusive OR.

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

     `TRUE' or `logical'.

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

     y <- 1 + (x <- rpois(50, lambda=1.5) / 4 - 1)
     x[(x > 0) & (x < 1)]    # all x values between 0 and 1
     if (any(x == 0) || any(y == 0)) "zero encountered"

