mids2spss {mice} | R Documentation |
Converts a mids
object into a format recognized by SPSS, and
writes the data and the SPSS syntax files.
mids2spss(imp, filedat = "midsdata.txt", filesps = "readmids.sps", path = getwd(), sep = "\t", dec = ".", silent = FALSE)
imp |
The |
filedat |
A character string describing the name of the output data file. |
filesps |
A character string describing the name of the output syntax file. |
path |
A character string containing the path of the output file. The
value in |
sep |
The separator between the data fields. |
dec |
The decimal separator for numerical data. |
silent |
A logical flag stating whether the names of the files should be printed. |
This function automates most of the work needed to export a
mids
object to SPSS. It uses a modified version of
writeForeignSPSS()
from the foreign
package. The
modified version allows for a choice of the field and decimal separators,
and makes some improvements to the formatting, so that the generated
syntax file is amenable to the INCLUDE
statement in SPSS.
Below are some things to pay attention to.
The SPSS
syntax file has the proper file names and separators set, so
in principle it should run and read the data without alteration. SPSS
is
more strict than R
with respect to the paths. Always use the
full path, otherwise SPSS
may not be able to find the data file.
Factors in R
translate into categorical variables in
SPSS
. The internal coding of factor levels used in R
is
exported. This is generally acceptable for SPSS
. However, when
the data are to be combined with existing SPSS
data, watch out
for any changes in the factor levels codes. The read.spss()
in
package foreign
for reading .sav
uses its own internal
numbering scheme 1,2,3,...
for the levels of a
factor. Consequently, changes in factor code can cause discrepancies
in factor level when re-imported to SPSS
. The solution is to
manually recode the factor level in SPSS
.
SPSS
will recognize the data set as a multiply imputed data
set, and do automatic pooling in procedures where that is
supported. Note however that pooling is an extra option only available
to those who licence the MISSING VALUES
module. Without this
licence, SPSS
will still recognize the structure of the data,
but not do any pooling.
The return value is NULL
.
Stef van Buuren, dec 2010.