cat                   package:base                   R Documentation

_C_o_n_c_a_t_e_n_a_t_e _a_n_d _P_r_i_n_t

_D_e_s_c_r_i_p_t_i_o_n:

     Outputs the objects, concatenating the representations.  'cat'
     performs much less conversion than 'print'.

_U_s_a_g_e:

     cat(... , file = "", sep = " ", fill = FALSE, labels = NULL,
         append = FALSE)

_A_r_g_u_m_e_n_t_s:

     ...: R objects (see Details for the types of objects allowed).

    file: A connection, or a character string naming the file to print
          to.  If '""' (the default), 'cat' prints to the standard
          output connection, the console unless redirected by 'sink'.
          If it is '"|cmd"', the output is piped to the command given
          by 'cmd', by opening a pipe connection. 

     sep: character string to insert between the objects to print.

    fill: a logical or (positive) numeric controlling how the output is
          broken into successive lines.  If 'FALSE' (default), only
          newlines created explicitly by '"\n"' are printed. 
          Otherwise, the output is broken into lines with print width
          equal to the option 'width' if 'fill' is 'TRUE', or the value
          of 'fill' if this is numeric.  Non-positive 'fill' values are
          ignored, with a warning.

  labels: character vector of labels for the lines printed. Ignored if
          'fill' is 'FALSE'.

  append: logical. Only used if the argument 'file' is the name of file
          (and not a connection or '"|cmd"'). If 'TRUE' output will be
          appended to 'file'; otherwise, it will overwrite the contents
          of 'file'.

_D_e_t_a_i_l_s:

     'cat' is useful for producing output in user-defined functions. It
     converts its arguments to character strings, concatenates them,
     separating them by the given 'sep=' string, and then outputs them.

     No linefeeds are output unless explicitly requested by '"\n"' or
     if generated by filling (if argument 'fill' is 'TRUE' or numeric.)

     Currently only atomic vectors (and so not lists) and names are
     handled.  Character strings are output 'as is' (unlike
     'print.default' which escapes non-printable characters and
     backslash - use 'encodeString' if you want to output encoded
     strings using 'cat').  Other types of R object should be converted
     (e.g. by 'as.character' or 'format') before being passed to 'cat'.

     'cat' converts numeric/complex vectors in the same way as 'print'
     (and not in the same way as 'as.character' which is used by the S
     equivalent), so 'options' '"digits"' and '"scipen"' are relevant.

_V_a_l_u_e:

     None (invisible 'NULL').

_R_e_f_e_r_e_n_c_e_s:

     Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) _The New S
     Language_. Wadsworth & Brooks/Cole.

_S_e_e _A_l_s_o:

     'print', 'format', and 'paste' which concatenates into a string.

_E_x_a_m_p_l_e_s:

     iter <- rpois(1, lambda=10)
     ## print an informative message
     cat("iteration = ", iter <- iter + 1, "\n")

     ## 'fill' and label lines:
     cat(paste(letters, 100* 1:26), fill = TRUE,
         labels = paste("{",1:10,"}:",sep=""))

