SASxport (version 1.2.3)

write.xport: Write Data to a SAS XPORT File

Description

This function writes one or more data frames into a SAS XPORT format library file.

Usage

write.xport(...,
            list=base::list(),
            file = stop("'file' must be specified"),
            verbose=FALSE,
            sasVer="7.00",
            osType,
            cDate=Sys.time(),
            formats=NULL,
            autogen.formats=TRUE
 )

Arguments

...

One or more data frames to be stored

list

A list containing data frames to be stored.

file

File name or connection object. Use "" to view the raw data

verbose

Logical flag controlling whether status is reported during processing

sasVer

SAS version string

osType

Opererating system, defaults to "R X.Y.Z" for appropriate values of X, Y, and Z

cDate

Date object specifying dataset creation date

formats

Optional data frame containing SAS format information.

autogen.formats

Logical indiciating whether SAS formats should be auto-generated for factor variables.

Value

• No return value

Details

The function creates a SAS XPORT data file (see reference) from one or more data frames. This file format imposes a number of constraints:

• Data set and variable names are truncated to 8 characters and converted to upper case. All characters outside of the set A-Z, 0-9, and '\_' are converted to '\_'.
• Character variables are stored as characters.
• Ifautogen.formats=TRUE(the default), factor variables are stored as numeric with an appropriate SAS format specification. Ifautogen.formats=FALSE, factor variables are stored as characters.
• All numeric variables are stored as double-precision floating point values utilizing the IBM mainframe double precision floating point format (see the reference).
• Date and time variables are either converted to number of days since 1960-01-01 (date only), or number of seconds since 1960-01-01:00:00:00 GMT (date-time variables).
• Missing values are converted to the standard SAS missing value '.'

In addition, the SAS XPORT format allows each variable to have a corresponding label, display format, and input format. To set these values, add the attribute 'label', 'SASformat', or 'SASiformat' to individual data frame variables. (See the example section.)

The actual translation of R objects to objects appropriate for SAS is handled by the toSAS generic and associated methods.

References

SAS Technical Support document TS-140: ``The Record Layout of a Data Set in SAS Transport (XPORT) Format'' available at http://ftp.sas.com/techsup/download/technote/ts140.html.

See Also

toSAS, lookup.xport, read.xport

Examples

#####
## R version of the example given in TS-140
#####

## manually create a data set
temp <- data.frame( x=c(1, 2, NA, NA ), y=c('a', 'B', NA, '*' ) )

## look at it
temp

## add a format specifier (not used by R)
attr(temp$x, 'SASformat') <- 'date7.'

## add a variable label (not used by R)
attr(temp$y, 'label')  <- 'character variable'

## verify the additions
str(temp)

## rename the data set
abc <- temp

# create a SAS XPORT file 
write.xport( abc, file="xxx.dat" )

# list the contents of the file
lookup.xport("xxx.dat")

## reload the data
xxx.abc <- read.xport("xxx.dat")

## and look at it
xxx.abc

## Note that the variable names have been converted to uppercase