

subset {base}                                R Documentation

_S_u_b_s_e_t_t_i_n_g _V_e_c_t_o_r_s _a_n_d _D_a_t_a _F_r_a_m_e_s

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

     subset(x, ...)
     subset.default(x, subset)
     subset.data.frame(x, subset, select)

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

       x: Object to be subsetted

     ...: How to subset, depends on object

  subset: logical expression

  select: expression, indicating variables to select from a
          dataframe

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

     For ordinary vectors, the result is simply `x[subset &
     !is.na(subset)]'.

     For dataframes, the `subset' argument works similarly
     on the rows.  Note that `subset' will be evaluated in
     the dataframe.

     The `select' argument exists only for dataframes.  It
     works by first replacing variable names in the selec-
     tion expression with the corresponding column numbers
     in the dataframe and then using the resulting integer
     vector to index the columns.  This allows the use of
     the standard indexing conventions so that e.g. ranges
     of variables can be specified easily.

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

     Selected rows and columns of the object `x'.

_A_u_t_h_o_r_(_s_)_:

     Peter Dalgaard

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

     `[', `transform'

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

     data(airquality)
     subset(airquality, Temp > 80, select = c(Ozone, Temp))
     subset(airquality, Day == 1, select = -Temp)
     subset(airquality, select = Ozone:Wind)

     attach(airquality)
     subset(Ozone, Temp > 80)

