Hi, I have been experimenting with the new Survey package. Specifically, I was trying to use some of the functions on the public-use survey data from NHIS (2000 Sample Adult file).
Error 1): The first error I get is when I try to specify the complex survey design. nhis.design<-svydesign(ids=~psu, probs=~probs, strata=~strata, data=nhis.df, check.strata=TRUE) Error in svydesign(ids = ~psu, probs = ~probs, strata = ~strata, data = nhis.df, : Clusters not nested in strata My data are sorted by strata, psu. Can someone tell me what the structure has to be for a stratified sample with clustering? Looking at the code, it appears to me that it does not allow more than 1 observation per psu [i.e. any(sc > 1)]. Error 2). If I go ahead and specify check.strata=FALSE, then svydesign runs ok. I then tried using the svymean function. In the following example, if I specify na.rm=TRUE, I get the error below: > svymean(nhis.df$crc10yr, design=nhis.design, na.rm=TRUE) Error in rowsum.default(x, strata) : Incorrect length for 'group' I traced this to the svyCprod call within svymean. SvyCprod calls rowsum and the group argument ("strata") appears to be the full length of that column rather than the subset with non-missing data. Error 3). I then tried svymean on another variable with na.rm=FALSE. I got the following error: > svymean(nhis.df$age, design=nhis.design) Error in drop(rval) : names attribute must be the same length as the vector I also traced this error to a call to rowsum within the function svyCprod. I'm not sure what names attribute this is referring to because the arguments to rowsum and the rval object do not appear to have a names attribute. Does anyone know what the problem here might be? Has anyone else used the survey package on public-use survey datasets like BRFSS or NHIS? Was there anything special you had to do to those datasets before specifying the survey design? I know that's a pretty vague question. If any of you are SUDAAN users, I basically mean does it have to be structured differently that what you pass into a SUDAAN procedure. Thanks in advance for any suggestions! I am using R 1.6.2 on Windows 2000. -Trevor ______________________________________________ [EMAIL PROTECTED] mailing list http://www.stat.math.ethz.ch/mailman/listinfo/r-help