read.table {base} | R Documentation |
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.
read.table(file, header = FALSE, sep = "", dec = ".", quote = "\"'", row.names, col.names, as.is = FALSE, na.strings = "NA", skip = 0) read.csv(file, header = TRUE, sep = ",", quote="\"", dec=".", row.names, col.names, as.is=FALSE, na.strings="", skip=0) read.csv2(file, header = TRUE, sep = ";", quote="\"", dec=",", row.names, col.names, as.is=FALSE, na.strings="", skip=0)
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 decimal point |
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. |
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.
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.
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
.
scan
,
read.fwf
for reading fixed width
formatted input;
write.table
;
data.frame
.