

Constants {base}                             R Documentation

_B_u_i_l_t_-_i_n _C_o_n_s_t_a_n_t_s

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

     LETTERS
     letters
     month.abb
     month.name
     pi

_V_a_l_u_e_:

     R has a limited number of built-in constants (there is
     also a rather larger library of data sets which can be
     loaded with the function `data').

     The following constants are available:

 LETTERS: the 26 upper-case letters of the Roman alphabet;

 letters: the 26 lower-case letters of the Roman alphabet;

month.abb: the three-letter abbreviations for the English
          month-names;

month.name: The English names for the months of the year;

      pi: the ratio of the circumference of a circle to its
          diameter.

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

     `data'.

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

      all(nchar(letters) == 1)                    # TRUE
      all(month.abb == substr(month.name, 1, 3))  # TRUE

     eps <- .Machine$double.eps
     all.equal(pi, 4*atan(1), tol= 2*eps)

     # John Machin (1705) computed 100 decimals of pi :
     all.equal(pi/4, 4*atan(1/5) - atan(1/239), 4*eps)

