Thanks, Bill. Sooo... taking the error literally,
temp1 = array(NA, c(3,2,1)) dimnames(temp1)[[3]] = list( "test" ) works, even though mode( dimnames(temp1)[[3]] ) yields "character". Setting all the dimension names simultaneously still feels way better. -- Sent from my phone. Please excuse my brevity. On March 21, 2017 9:40:55 AM PDT, William Dunlap <[email protected]> wrote: >It happens because dimnames(originalArray) is NULL and when [[<- >extends >NULL it turns it into a list if the size of the new element is not one >but into a vector with the type of new element if the new element's >size is one. > > str( `[[<-`(NULL, 3, value="One") ) > chr [1:3] NA NA "One" > > str( `[[<-`(NULL, 3, value=c("One","Two") )) > List of 3 > $ : NULL > $ : NULL > $ : chr [1:2] "One" "Two" > > str( `[[<-`(NULL, 3, value=character(0) )) > List of 3 > $ : NULL > $ : NULL > $ : chr(0) >dimnames(x) <- characterVector could be changed to call as.list() on >its right hand side. That would help in this case but would cover up >usage errors in other cases. > > >Bill Dunlap >TIBCO Software >wdunlap tibco.com > > >On Tue, Mar 21, 2017 at 9:29 AM, Jeff Newmiller ><[email protected]> wrote: >> While I generally agree that it is better to design code that sets >all of the dimension names simultaneously, the discrepancy between >behavior when the dimensions are longer than 1 and when they are equal >to 1 seems irregular. Someone went to some lengths to make it possible >to set dimnames individually "most" of the time and it is not clear to >me why they stopped short of all the time. >> -- >> Sent from my phone. Please excuse my brevity. >> >> On March 21, 2017 8:21:32 AM PDT, David Winsemius ><[email protected]> wrote: >>> >>>> On Mar 20, 2017, at 4:46 PM, Douglas Ezra Morrison >>><[email protected]> wrote: >>>> >>>> Dear R-Help readers, >>>> >>>> I am writing to ask about some behavior of base::dimnames() that >>>surprised >>>> me. If I create an array with one of its dimensions = 1, and then >try >>>to >>>> assign names to that dimension, I get an error unless I name one of >>>the >>>> other dimensions first. For example: >>>> >>>>> temp1 = array(NA, c(3,2,1)) >>>>> dimnames(temp1)[[3]] = "test" >>>> >>>> results in the error: "Error in dimnames(temp1)[[3]] = "test" : >>>'dimnames' >>>> must be a list" >>>> >>>> However, the following works: >>>> >>>>> temp1 = array(NA, c(3,2,1)) >>> >>>Why not: >>> >>>temp1 = array(NA, c(3,2,1)) >>>dimnames(temp1) <- list(NULL,NULL,"test") >>> >>> >>>>> dimnames(temp1)[[2]] = c("a","b") >>>>> dimnames(temp1)[[3]] = "test" >>>> >>>> I found an explanation of what is happening on stackoverflow ( >>>> >>>http://stackoverflow.com/questions/12578461/r-dimnames-of-matrix-strange-behaviour/42915723), >>>> however, I didn't see any explanation of why this behavior is >>>> intended/desirable. Moreover, it recently caused a problem in a >place >>>where >>>> I couldn't easily work around it, without submitting edits to or >>>forking >>>> someone else's R package. Is there any possibility that this >behavior >>>is a >>>> bug that could be fixed, or is it something I should learn to live >>>with? >>> >>>I doubt that a request for changing the behavior of the `dimnames.<-` >>>function will get very far. Learn to use the language as it's >designed. >>> >>>David. >>> >>>> >>>> Thanks, >>>> Doug >>>> >>>> -- >>>> >>>> Typed from a mobile device - apologies for typos and brevity. >>>> >>>> [[alternative HTML version deleted]] >>>> >>>> ______________________________________________ >>>> [email protected] 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. >>> >>>David Winsemius >>>Alameda, CA, USA >>> >>>______________________________________________ >>>[email protected] 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. >> >> ______________________________________________ >> [email protected] 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. ______________________________________________ [email protected] 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.
