[Rcpp-devel] Locating an Instance of a Reference Class in the Environment

Hi Matthew,

Thanks for circling back!

On 28 March 2023 at 11:23, Matthew Supernaw - NOAA Federal wrote:
| Hi Dirk,
| Thanks for your attention on this. I was able to find a solution that
works for
| us.
| Matthew
|
| https://github.com/NOAA-FIMS/ModularTMBExample/blob/map/src/
| tmb_objective_function.cpp#L133

Ok -- if you want we can maybe offline work on smoothing that over. You
have
Rcpp already at your disposal there, you should not need the darn PROTECT
and
UNPROTECT that makes my eyes burn.

Total aside:  I needed a finger exercise for turning factor to character
and
vice verse and just did this (for now (?) in RcppExamples):

https://github.com/eddelbuettel/rcppexamples/blob/master/src/makeFactor.cpp

and looks like I forgot to rename the file which I may do to
FactorExample.cpp

Dirk

| On Fri, Mar 24, 2023 at 4:36 PM Jeff Newmiller <jdnewmil at dcn.davis.ca.us

| wrote:
|
|     Well, feel free to ignore my post, but the gist was that anything
you have
|     access to in R can be passed by your R API code to your Rcpp code.
Also,
|     due to R's GC you should usually avoid caching references between
calls to
|     your Rcpp code anyway.
|
|     On March 24, 2023 12:40:43 PM PDT, Matthew Supernaw - NOAA Federal <
|     matthew.supernaw at noaa.gov> wrote:
|     >Hi Jeff,
|     >I'm not sure I understand your comment. The code is part of a
package.
|     >We're just trying to sync the declared object name in the R
environment to
|     >the object in the Rcpp module programmatically from c++ for
internal use.
|     I
|     >just wondered if there was a way to access the wrapped object in the
|     >Rcpp:::PreserveStorage class and Dirk answered that question.
|     >Thanks.
|     >Matthew
|     >
|     >
|     >On Fri, Mar 24, 2023 at 2:34 PM Jeff Newmiller <
jdnewmil at dcn.davis.ca.us>
|     >wrote:
|     >
|     >> Matthew... the normal context for sharing Rcpp code is within a
package.
|     >> It is a no-brainer to have an R API called by the user that calls
|     whatever
|     >> Rcpp code it needs to, which is why your objection seems
inappropriate
|     to
|     >> me.
|     >>
|     >> On March 24, 2023 10:43:34 AM PDT, Dirk Eddelbuettel <
edd at debian.org>
|     >> wrote:
|     >> >
|     >> >On 24 March 2023 at 13:08, Matthew Supernaw - NOAA Federal wrote:
|     >> >| I'm sure it's possible to do from the R side, however, the
|     requirement
|     >> is to
|     >> >| hide this from the end user and set the reference objects name
to the
|     >> declared
|     >> >| name from the R environment. If I view the environment in
RStudio,
|     >> there is
|     >> >| much more information available. ls() only returns a list of
objects
|     by
|     >> their
|     >> >| declared name. I'm wondering how to get more details about
elements
|     in
|     >> the
|     >> >| environment.
|     >> >
|     >> >Thanks for additional color.  That may be a very interesting and
|     valuable
|     >> >question _for the C API of R_ and youe guess of "maybe Rcpp has a
|     helper"
|     >> is
|     >> >a good one.  Sadly, I fear we may not have anything for you.
|     >> >
|     >> >Dirk
|     >> >
|     >> >--
|     >> >dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org
|     >> >_______________________________________________
|     >> >Rcpp-devel mailing list
|     >> >Rcpp-devel at lists.r-forge.r-project.org
|     >> >
https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
|     >> --
|     >> Sent from my phone. Please excuse my brevity.
|     >>
|     >
|     >
|
|     --
|     Sent from my phone. Please excuse my brevity.
|
|
|
| --
| Matthew Supernaw
| Scientific Software Developer
| National Oceanic and Atmospheric Administration
| Office Of Science and Technology
| NOAA Fisheries | U.S. Department of Commerce
| Phone 248 - 396 - 7797
|
|

--
dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org