R: Data Output

write.table {base} | R Documentation

## Data Output

### Description

`write.table` prints its required argument `x` (after converting it to a data frame if it is not one already) to `file`. The entries in each line (row) are separated by the value of `sep`.

### Usage

    write.table(x, file = "", append = FALSE, quote = TRUE, sep = " ",
                eol = "\n", na = "NA", dec = ".", row.names = TRUE,
                col.names = TRUE, qmethod = c("escape", "double"))

### Arguments

`x` | the object to be written, typically a data frame. If not, it is attempted to coerce `x` to a data frame.
`file` | either a character string naming a file or a connection. `""` indicates output to the console.
`append` | logical. If `TRUE`, the output is appended to the file. If `FALSE`, any existing file of the name is destroyed.
`quote` | a logical 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 the variable (columns) to quote. In both cases, row and columns names are quoted if they are written, but not if `quote is FALSE`.
`sep` | the field separator string. Values within each row of `x` are separated by this string.
`eol` | the character(s) to print at the end of each line (row).
`na` | the string to use for missing values in the data.
`dec` | the string to use for decimal points.
`row.names` | either a logical value indicating whether the row names of `x` are to be written along with `x`, or a character vector of row names to be written.
`col.names` | either a logical value indicating whether the column names of `x` are to be written along with `x`, or a character vector of column names to be written.
`qmethod` | a character string specifying how to deal with embedded double quote characters when quoting strings. Must be one of `"escape"` (default), in which case the quote character is escaped in C style by a backslash, or `"double"`, in which case it is doubled. You can specify just the initial letter.

### Details

Normally there is no column name for a column of row names. If `col.names=NA` a blank column name is added. This can be used to write CSV files for input to spreadsheets.

`write.table` can be slow for data frames with large numbers (hundreds or more) of columns: this is inevitable as each column could be of a different class and so must be handled separately. Function `write.matrix` in package `MASS` may be much more efficient if `x` is a matrix or can be represented in a numeric matrix.

### See Also

The `R Data Import/Export' manual.

`read.table`, `write`.

`write.matrix`.

### Examples

    ## To write a CSV file for input to Excel one might use
    write.table(x, file = "foo.csv", sep = ",", col.names = NA)
    ## and to read this file back into R one needs
    read.table("file.csv", header = TRUE, sep = ",", row.names=1)

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