# write.dta

##### Write Files in Stata Binary Format

Writes the data frame to file in the Stata binary
format. Does not write array variables unless they can be
`drop`

-ed to a vector.

- Keywords
- file

##### Usage

```
write.dta(dataframe, file, version = 7L,
convert.dates = TRUE, tz = "GMT",
convert.factors = c("labels", "string", "numeric", "codes"))
```

##### Arguments

- dataframe
- a data frame.
- file
- character string giving filename.
- version
- integer: Stata version: 6, 7, 8 and 10 are supported, and 9 is mapped to 8, 11 to 10.
- convert.dates
- Convert
`Date`

and`POSIXt`

objects to Stata dates? - tz
- timezone for date conversion
- convert.factors
- how to handle factors

##### Details

The major differences between file formats in Stata versions is that
version 7.0 and later allow 32-character variable names (5 and 6 were
restricted to 8-character name). The `abbreviate`

function is
used to trim long variables to the permitted length. A warning is
given if this is needed and it is an error for the abbreviated names
not to be unique.

The columns in the data frame become variables in the Stata data set. Missing values are handled correctly.

Unless deselected by argument `convert.dates`

, Rdate and
date-time objects (`POSIXt`

classes) are converted into the Stata
format. For date-time objects this may lose information -- Stata
dates are in days since 1960-1-1. `POSIXct`

objects can be
written without conversion but will not be understood as dates by
Stata; `POSIXlt`

objects cannot be written without conversion.

There are four options for handling factors. The default is to use
Stata `convert.factors="string"`

, the factor levels are written as
strings. With `convert.factors="numeric"`

the numeric values of
the levels are written, or `NA`

if they cannot be coerced to
numeric. Finally, `convert.factors="codes"`

writes the
underlying integer codes of the factors. This last used to be the
only available method and is provided largely for backwards
compatibility.

For Stata 8 or later use the default `version=7`

-- the only
advantage of Stata 8 format is that it can represent multiple
different missing value types, and Rdoesn't have them. Stata 10/11
allows longer format lists, but Rdoes not make use of them.

Note that the Stata formats are documented to use ASCII strings -- Rdoes not enforce this, but use of non-ASCII character strings will not be portable as the encoding is not recorded. Up to 244 bytes are allowed in character data, and longer strings will be truncated with a warning.

Stata uses some large numerical values to represent missing
values. This function does not currently check, and hence integers
greater than `2147483620`

and doubles greater than
`8.988e+307`

may be misinterpreted by Stata.

##### Value

`NULL`

##### References

Stata 6.0 Users Manual, Stata 7.0 Programming manual, Stata online
help (version 8 and later, also

##### See Also

##### Examples

```
write.dta(swiss, swissfile <- tempfile())
read.dta(swissfile)
```

*Documentation reproduced from package foreign, version 0.8-47, License: GPL (>= 2)*