[R] Identify command in R]

[Barry Rowlingson]

2008/11/20 David Kaplan <dkaplan at education.wisc.edu>:
> Let me try to be more specific.
>
> The x y coordinates are different because of NAs in the dataset.  In this
> analysis, a set of hat values (a measure of influence in regression) is
> given for each observation.  On the basis of the regression that was run to
> get these hat values, the sample size was 1164 (one removed due to NA).  The
> length of the data set is 1165.  If I remove the NA from the data set, I can
> get identify to run.  What I would like to know is if there is a way to get
> identify to ignore the NAs?

 Still not clear. Your failing example was:

   identify(1:1165, hatvalues(scireg3),row.names(sciach))

 So are you saying that hatvalues(scireg3) is of length 1164? What you
really want is for hatvalues to return NA in the places where you have
missing data. identify is quite happy with NA values - try:

 > x=1:10
 > y=runif(10);y[5]=NA
 > plot(x,y)
 > identify(x,y)

 If you can't change hatvalues to do this, then you'll just have to
remove the corresponding values of 1:1165 so that it is of length
1164. So something like:

 okdata = !is.na(dataset)
 plot((1:1165)[okdata],hatvalues(dataset))


Barry