charmatch                package:base                R Documentation

_P_a_r_t_i_a_l _S_t_r_i_n_g _M_a_t_c_h_i_n_g

_D_e_s_c_r_i_p_t_i_o_n:

     'charmatch' seeks matches for the elements of its first argument
     among those of its second.

_U_s_a_g_e:

     charmatch(x, table, nomatch = NA_integer_)

_A_r_g_u_m_e_n_t_s:

       x: the values to be matched: converted to a character vector by
          'as.character'.

   table: the values to be matched against: converted to a character
          vector.

 nomatch: the (integer) value to be returned at non-matching positions.

_D_e_t_a_i_l_s:

     Exact matches are preferred to partial matches (those where the
     value to be matched has an exact match to the initial part of the
     target, but the target is longer).

     If there is a single exact match or no exact match and a unique
     partial match then the index of the matching value is returned; if
     multiple exact or multiple partial matches are found then '0' is
     returned and if no match is found then 'nomatch' is returned.

     'NA' values are treated as the string constant '"NA"'.

     Inputs with embedded nul bytes will be truncated at the first nul.

_V_a_l_u_e:

     An integer vector of the same length as 'x', giving the indices of
     the elements in 'table' which matched, or 'nomatch'.

_A_u_t_h_o_r(_s):

     This function is based on a C function written by Terry Therneau.

_S_e_e _A_l_s_o:

     'pmatch', 'match'.

     'grep' or 'regexpr' for more general (regexp) matching of strings.

_E_x_a_m_p_l_e_s:

     charmatch("", "")                             # returns 1
     charmatch("m",   c("mean", "median", "mode")) # returns 0
     charmatch("med", c("mean", "median", "mode")) # returns 2

