Marion Wenty
2012-Jul-25 16:48 UTC
[R] Memisc package: imported varibles from SPSS have got wrong measurement
Dear list members, I have got another problem. I imported an SPSS file with the Memisc package using the following commands: mz <- spss.system.file("myspssfile.sav") mz <- subset(mz,select=c( bsex,balt,xurb,dtaet,kartab,bgeb,boseit,bgeblan,xnuts2,kausb,xerwstat, asbper,asbhh,ajahr,aquartal,bstaat,xwieoft,gew1,apkz,bpkzm,bpkzv)) Afterwards I checked the measurements of the variables 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 contain numbers in the SPSS file (e.g. the age of a person) - and no NAs - but have got the measurement "nominal"! Does anyone know why this is happening? Thank you very much for your help in advance! Marion -- Mag.a Marion Wenty Wissenschaftliche Mitarbeiterin Institut für Kinderrechte und Elternbildung Ballgasse 2, 6. Stock 1010 Wien [[alternative HTML version deleted]]
David Winsemius
2012-Jul-26 00:35 UTC
[R] Memisc package: imported varibles from SPSS have got wrong measurement
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 > package > using the following commands: > > mz <- spss.system.file("myspssfile.sav") > > mz <- subset(mz,select=c( > bsex,balt,xurb,dtaet,kartab,bgeb,boseit,bgeblan,xnuts2,kausb,xerwstat, > asbper,asbhh,ajahr,aquartal,bstaat,xwieoft,gew1,apkz,bpkzm,bpkzv))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 variablesWhat 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 > contain > 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 measurement(mz$age_variable) <- "interval" # where age_variable is the unstated item in that "select" list -- David Winsemius, MD