read.table               package:base               R Documentation

_D_a_t_a _I_n_p_u_t

_D_e_s_c_r_i_p_t_i_o_n:

     Reads a file in table format and creates a data frame from it,
     with cases corresponding to lines and variables to fields in the
     file.

_U_s_a_g_e:

     read.table(file, header = FALSE, sep = "", quote = "\"'", dec = ".",
                row.names, col.names, as.is = FALSE, na.strings = "NA",
                skip = 0, check.names = TRUE, strip.white = FALSE)

     read.csv(file, header = TRUE, sep = ",", quote="\"", dec=".", ...)

     read.csv2(file, header = TRUE, sep = ";", quote="\"", dec=",", ...)

_A_r_g_u_m_e_n_t_s:

    file: the name of the file which the data are to be read from. Each
          row of the table appears as one line of the file.  If it does
          not contain an absolute path, the file name is relative to
          the current working directory, `getwd()'.

  header: a logical value indicating whether the file contains the
          names of the variables as its first line.

     sep: the field separator character.  Values on each line of the
          file are separated by this character.

   quote: the set of quoting characters. To disable quoting altogether,
          use `quote=""'.

     dec: the character used in the fike for decimal points.

row.names: a vector of row names.  This can be a vector giving the
          actual row names, or a single number giving the column of the
          table which contains the row names, or character string
          giving the name of the table column containing the row names.

col.names: a vector of optional names for the variables. The default is
          to use `"V"' followed by the column number.

   as.is: the default behavior of `read.table' is to convert
          non-numeric variables to factors.  The variable `as.is'
          controls this conversion.  Its value is either a vector of
          logicals (values are recycled if necessary), or a vector of
          numeric indices which specify which columns should be left as
          character strings.

na.strings: a vector strings which are to be interpreted as `NA'
          values.

    skip: the number of lines of the data file to skip before beginning
          to read data.

check.names: logical. If `TRUE' then the names of the variables in the
          data frame are checked to ensure that they are valid variable
          names.  If necessary they are adjusted (by `make.names') so
          that they are.

skip.white: logical. Used only when `sep' has been specified, and
          allows the stripping of leading and trailing white space from
          `character' fields (`numeric' fields are always stripped). 
          See `scan' for further details, remembering that the columns
          may include the row names.

     ...: Further arguments to `read.table'.

_D_e_t_a_i_l_s:

     `read.csv' and `read.csv2' are identical to `read.table' except
     for the defaults. They are intended for reading "comma separated
     variable" files (.csv) or the variant used in countries that use
     comma as decimal point and consequently semicolon as field
     separator.  Notice that `header=TRUE' in these variants.

_V_a_l_u_e:

     A data frame (`data.frame') containing a representation of the
     data in the file.

     This function is the principal means of reading tabular data into
     R.

_N_o_t_e:

     The implementation of `read.table' currently reads everything as
     character using `scan' and subsequently defines `"numeric"' or
     `factor' variables.

     This is quite memory consuming for files of thousands of records
     and may need larger memory, see `Memory'.

_S_e_e _A_l_s_o:

     `scan', `read.fwf' for reading fixed width formatted input;
     `write.table'; `data.frame'.

