[R] Memisc package: imported varibles from SPSS have got wrong measurement
dwinsemius at comcast.net
Thu Jul 26 02:35:57 CEST 2012
On Jul 25, 2012, at 9:48 AM, Marion Wenty wrote:
> Dear list members,
> I have got another problem. I imported an SPSS file with the Memisc
> using the following commands:
> mz <- spss.system.file("myspssfile.sav")
> mz <- subset(mz,select=c(
The memisc package help file for spss.system.file() (actually labeled
"importers") says that there is an S4 method for "subset" there does
not seem to be a separate page describing its behavior or values
> Afterwards I checked the measurements of the variables
What does that phrase mean? What code did you actually use?
> and they are all
> right for most of them (e.g. the variable containing the sex of a
> person is
> "nominal" and the variable containing the year is "interval"). For
> two of
> the variables the measurement is not o.k, though. They exclusively
> numbers in the SPSS file (e.g. the age of a person) - and no NAs -
> but have
> got the measurement "nominal"!
Hard to say. There is no R storage mode that is called "nominal".
Perhaps some sort of memisc-specific terminology? Or perhaps something
in your spss dataset... to which you have not provided access? Or the
default setting for the spss.system.file access method? I know that
the Hmisc package's describe() function will report out a variable as
though it were categorical if there are only 8 or fewer unique values.
After looking at further help pages and trying the help pages code, I
am guessing that some of my puzzlement might be answered by reading
the vignettes, but you can do that yourself.
Here's a hackish guess ... try:
measurement(mz$age_variable) <- "interval"
# where age_variable is the unstated item in that "select" list
David Winsemius, MD
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