S-PLUS Files
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Stat/Transfer will read and write S-PLUS data sets.  Files written on 64 bit machines such as the DEC Alpha are not supported.


Standard extension:  [none]


Reading S-PLUS files

Because the S-PLUS file format is so unstructured that it allows the user to write almost anything, including code, into it, Stat/Transfer imposes a few restrictions on input files.  Specifically, your data should be in one of the following formats:


       two dimensional matrices

       vectors

       factors

       dataframes


S-PLUS writes out its data in the native format of the machine on which it is running.  This means that both the byte order and the width of numbers can vary between machines.  On input, Stat/Transfer will automatically sense the byte order of the machine that wrote the file.


Writing S-PLUS files

On output, Stat/Transfer writes a S-PLUS dataframe.  If your input data set does not have a variable named 'rownames', Stat/Transfer will create an extra variable containing the case number, stored as an integer variable and named 'rownames'.


Factors in S-PLUS consist of a vector of zero-based numeric values and a vector of string labels that are mapped onto the values.  You can choose to have these written to an output file as the numeric values and their value labels or you can write them as strings.  This option is controlled in the R and S-Plus Options section of the Options dialog box.   If you are going to a package such a Stata or SPSS, that supports value labels, the first option is more appropriate.


You can choose whether you want to write out a file with low to high byte order, appropriate for such processors as Intel or DEC, or a file with high to low byte order, for such processors as SPARC, HP, or Motorola.  If you are using the Windows version of S-PLUS, select Intel (low to high) byte order on output.


Missing Data

S-PLUS supports missing values.  On input, missing values are converted to the internal missing value in Stat/Transfer.  On output, missing values are converted to the value appropriate for each variable type.


Output Variable Types

The output variable type that results from each target variable type is given in the following table:



Target Type

Output Type


byte

int

long

Integer


float

Real


double

Double


string

String


date

Date


time

date/time

Character (written using ASCII format options currently in effect)