I have been informed by CRAN administrators that the development
version of R issues warnings for my package(s). Some are easy to mend
(such as Internet links not working anymore), but this one I don't
know how to avoid:
Error in if (class(e) == "try-error") { : the condition has length
> 1
I understand that `class` can return more than one value. But what
would be the appropriate way to catch an error in a construct like
this:
e <- try(b <- solve(a), silent=TRUE)
if (class(e) == "try-error") {
# ... do something
}
Should I instead compare the class with "matrix" or "array"
(or
both)?. That is, in each case check with a correct result class
instead of an error?
Thanks, HW
>>>>> "HW" == Hans W Borchers <hwborchers at gmail.com> writes:HW> I have been informed by CRAN administrators that the development HW> version of R issues warnings for my package(s). Some are easy to mend HW> (such as Internet links not working anymore), but this one I don't HW> know how to avoid: HW> Error in if (class(e) == "try-error") { : the condition has length > 1 HW> I understand that `class` can return more than one value. But what HW> would be the appropriate way to catch an error in a construct like HW> this: HW> e <- try(b <- solve(a), silent=TRUE) HW> if (class(e) == "try-error") { HW> # ... do something HW> } HW> Should I instead compare the class with "matrix" or "array" (or HW> both)?. That is, in each case check with a correct result class HW> instead of an error? HW> Thanks, HW You should probably use if (inherits(e, "try-error")) { # ... do something } kind regards ENrico -- Enrico Schumann Lucerne, Switzerland http://enricoschumann.net
See ?try which links you to ?tryCatch for the preferred approach. Alternatively: if(inherits(e, "try-error")) .... ## should work and satisfy CRAN -- Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Sun, Dec 15, 2019 at 6:21 AM Hans W Borchers <hwborchers at gmail.com> wrote:> I have been informed by CRAN administrators that the development > version of R issues warnings for my package(s). Some are easy to mend > (such as Internet links not working anymore), but this one I don't > know how to avoid: > > Error in if (class(e) == "try-error") { : the condition has length > 1 > > I understand that `class` can return more than one value. But what > would be the appropriate way to catch an error in a construct like > this: > > e <- try(b <- solve(a), silent=TRUE) > if (class(e) == "try-error") { > # ... do something > } > > Should I instead compare the class with "matrix" or "array" (or > both)?. That is, in each case check with a correct result class > instead of an error? > > Thanks, HW > > ______________________________________________ > R-help at 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. >[[alternative HTML version deleted]]
Yes, CRAN did accept 'if(inherits(e, "try-error"))'. I remember now, when I used the try-construct the first time, I also saw tryCatch and found it a bit too extensive for my purposes. Will look at it again when needed. Thanks to you and Enrico On Sun, 15 Dec 2019 at 16:03, Bert Gunter <bgunter.4567 at gmail.com> wrote:> > See ?try which links you to ?tryCatch for the preferred approach. > > Alternatively: if(inherits(e, "try-error")) .... ## should work and satisfy CRAN > > -- Bert > > > Bert Gunter > > "The trouble with having an open mind is that people keep coming along and sticking things into it." > -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) > > > On Sun, Dec 15, 2019 at 6:21 AM Hans W Borchers <hwborchers at gmail.com> wrote: >> >> I have been informed by CRAN administrators that the development >> version of R issues warnings for my package(s). Some are easy to mend >> (such as Internet links not working anymore), but this one I don't >> know how to avoid: >> >> Error in if (class(e) == "try-error") { : the condition has length > 1 >> >> I understand that `class` can return more than one value. But what >> would be the appropriate way to catch an error in a construct like >> this: >> >> e <- try(b <- solve(a), silent=TRUE) >> if (class(e) == "try-error") { >> # ... do something >> } >> >> Should I instead compare the class with "matrix" or "array" (or >> both)?. That is, in each case check with a correct result class >> instead of an error? >> >> Thanks, HW >> >> ______________________________________________ >> R-help at 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.