write.table prints its required argument x (after
converting it to a data frame if it is not one nor a matrix) to
a file or connection.write.table(x, file = "", append = FALSE, quote = TRUE, sep = " ",
eol = "
", na = "NA", dec = ".", row.names = TRUE,
col.names = TRUE, qmethod = c("escape", "double"),
fileEncoding = "")write.csv(...)
write.csv2(...)
x to a data frame."" indicates output to the console.file is a character
string. If TRUE, the output is appended to the
file. If FALSE, any existing file of the name is destroyed.TRUE or FALSE) or a
numeric vector. If TRUE, any character or factor columns
will be surrounded by double quotes. If a numeric vector, its
elements are taken as the indices of columns to quote. In both
cases, row and column names are quoted if they are written. If
FALSE, nothing is quoted.x are separated by this string.eol = "\r
" will produce Windows' line endings on
a Unix-alike OS, and eol = "\r" will produce files as expected by
Excel:mac 2004.x are to be written along with x, or a
character vector of row names to be written.x are to be written along with x, or a
character vector of column names to be written. See the section on
col.names = NA."escape" (default for write.table), in which case the
quote character is escaped in C style by a backslash, or
"double" (default for write.csv and
write.csv2), in which case it is doubled. You can specify
just the initial letter.file.write.table: append,
col.names, sep, dec and qmethod
cannot be altered.col.names = NA and row.names = TRUE a blank column name
is added, which is the convention used for CSV files to be read by
spreadsheets. Note that such CSV files can be read in Rby
read.csv(file = " write.csv and write.csv2 provide convenience wrappers
for writing CSV files. They set sep and dec (see
below), qmethod = "double", and col.names to NA
if row.names = TRUE (the default) and to TRUE otherwise.
write.csv uses "." for the decimal point and a comma for
the separator.
write.csv2 uses a comma for the decimal point and a semicolon for
the separator, the Excel convention for CSV files in some Western
European locales.
These wrappers are deliberately inflexible: they are designed to
ensure that the correct conventions are used to write a valid file.
Attempts to change append, col.names, sep,
dec or qmethod are ignored, with a warning.
CSV files do not record an encoding, and this causes problems if they
are not ASCII for many other applications. Windows Excel 2007/10 will
open files (e.g., by the file association mechanism) correctly if they
are ASCII or UTF-16 (use fileEncoding = "UTF-16LE") or perhaps
in the current Windows codepage (e.g., "CP1252"), but the
There is an IETF RFC4180 (write.csv writes compliant files on Windows: use
eol = "\r
" on other platforms.
row.names = TRUE, and vice versa.Real and complex numbers are written to the maximal possible precision.
If a data frame has matrix-like columns these will be converted to
multiple columns in the result (via as.matrix)
and so a character col.names or a numeric quote should
refer to the columns in the result, not the input. Such matrix-like
columns are unquoted by default.
Any columns in a data frame which are lists or have a class
(e.g., dates) will be converted by the appropriate as.character
method: such columns are unquoted by default. On the other hand,
any class information for a matrix is discarded and non-atomic
(e.g., list) matrices are coerced to character.
Only columns which have been converted to character will be quoted if
specified by quote.
The dec argument only applies to columns that are not subject
to conversion to character because they have a class or are part of a
matrix-like column (or matrix), in particular to columns protected by
I(). Use options("OutDec") to control
such conversions.
In almost all cases the conversion of numeric quantities is governed
by the option "scipen" (see options), but with
the internal equivalent of digits = 15. For finer control, use
format to make a character matrix/data frame, and call
write.table on that.
These functions check for a user interrupt every 1000 lines of output.
If file is a non-open connection, an attempt is made to open it
and then close it after use.
To write a Unix-style file on Windows, use a binary connection
e.g.file = file("filename", "wb").
write.matrix in package
## To write a CSV file for input to Excel one might use
x <- data.frame(a = I("a \" quote"), b = pi)
write.table(x, file = "foo.csv", sep = ",", col.names = NA,
qmethod = "double")
## and to read this file back into R one needs
read.table("foo.csv", header = TRUE, sep = ",", row.names = 1)
## NB: you do need to specify a separator if qmethod = "double".
### Alternatively
write.csv(x, file = "foo.csv")
read.csv("foo.csv", row.names = 1)
## or without row names
write.csv(x, file = "foo.csv", row.names = FALSE)
read.csv("foo.csv")
## To write a file in Mac Roman for simple use in Mac Excel 2004/8
write.csv(x, file = "foo.csv", fileEncoding = "macroman")
## or for Windows Excel 2007/10
write.csv(x, file = "foo.csv", fileEncoding = "UTF-16LE")Run the code above in your browser using DataLab