Great! thank you! Sincerely, Erin
On Fri, Jan 9, 2015 at 2:36 PM, Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > On 09/01/2015 2:04 PM, Erin Hodgess wrote: > > One more thing, please: (just like Columbo) > > > > Is there a work-around for this, please? > > I did some work with John Nash a few months ago that gave symbolic > derivative code that was a bit more flexible than the built-in code. > It's on R-forge in the nls14 package. > > With that package, you get the same error as in base, but you can do > > newDeriv(`[`(x,y), stop("no derivative when indexing")) > > and then fnDeriv() (the nls14 replacement for deriv()) works on your > example. > > Duncan Murdoch > > > > > Thanks again, > > Erin > > > > > > On Fri, Jan 9, 2015 at 1:09 PM, Richard M. Heiberger <r...@temple.edu> > wrote: > > > >> `[` is a function. So the deriv program is seeing > >> > >> `[`(y,3)*r1 + r2 > >> > >>> letters[5] > >> [1] "e" > >>> `[`(letters, 5) > >> [1] "e" > >> > >> On Fri, Jan 9, 2015 at 12:31 PM, Erin Hodgess <erinm.hodg...@gmail.com> > >> wrote: > >>> Hello! > >>> > >>> I have the following: > >>> > >>> zzz <- expression(y[3]*r1 + r2) > >>> deriv(zzz,c("r1","r2")) > >>> Error in deriv.default(zzz,c("r1","r2")) : > >>> Function '`[`' is not in the derivatives table > >>> > >>> What am I missing, please? Since y is not one of the variables that is > >>> being "acted upon", why is the [] an issue, please? > >>> > >>> Thank you for any help! > >>> > >>> Sincerely, > >>> Erin > >>> > >>> > >>> -- > >>> Erin Hodgess > >>> Associate Professor > >>> Department of Mathematical and Statistics > >>> University of Houston - Downtown > >>> mailto: erinm.hodg...@gmail.com > >>> > >>> [[alternative HTML version deleted]] > >>> > >>> ______________________________________________ > >>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > >>> https://stat.ethz.ch/mailman/listinfo/r-help > >>> PLEASE do read the posting guide > >> http://www.R-project.org/posting-guide.html > >>> and provide commented, minimal, self-contained, reproducible code. > >> > > > > > > > > -- Erin Hodgess Associate Professor Department of Mathematical and Statistics University of Houston - Downtown mailto: erinm.hodg...@gmail.com [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.