[Rcpp-devel] Rcpp-devel Digest, Vol 12, Issue 8

On 8 October 2010 at 04:28, Christian Gunning wrote:
| Yes, I've used this successfully. ?I have run into trouble extracting
| elements of length>1 from lists with variable-length elements, e.g.
| _mylist = list(a=1, b=1:3), mylist["a"] works but mylist["b"] is
| squirrely.

Please send a reproducible test case. ?I use the same approach a lot and have
not had issues.

Ah. I see now that, in the example above, mylist["a"] is a 1-length
NumericVector and (mylist["b"])[1] is a double.  My confustion was
using (mylist["b"])[1] in places that expected a NumericVector (like
Rf_PrintValue() or return() ), or trying to pull the single element
into a NumericVector:

NumericVector i(mylist["b]);

which, of course, initializes a NumericVector of length mylist["b"].

Thanks,
Christian