Re: [R] Tables without names
On 11/06/2009 5:35 PM, Stavros Macrakis wrote: A table without names displays like a vector: unname(table(2:3)) [1] 1 1 1 and preserves the table class (as with unname in general): dput(unname(table(2:3))) structure(c(1L, 1L), .Dim = 2L, class = table) Does that make sense? R is not consistent in its treatment of such unname'd tables: One of the complaints about the S3 object system is that anything can claim to be of class foo, even if it doesn't have the right structure so that foo methods work for it. I think that's all you're seeing here: you've got something that is mislabelled as being of class table. The solution is don't do that. In plot, they are considered erroneous input: plot(unname(table(2:3))) Error in xy.coords(x, y, xlabel, ylabel, log) : 'x' and 'y' lengths differ but in melt, they act as though they have names 1:n: melt(unname(table(2:3))) indicies value 11 1 22 1 (By the way, is the spelling error built into too much code to be corrected?) -s PS What is the standard way of extracting just the underlying vector? c(unname(...)) works -- is that what is recommended? I would use as.numeric(), but I don't claim it's standard. Duncan Murdoch __ R-help@r-project.org mailing list 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.
Re: [R] Tables without names
DM == Duncan Murdoch murd...@stats.uwo.ca on Fri, 12 Jun 2009 06:09:14 -0400 writes: DM On 11/06/2009 5:35 PM, Stavros Macrakis wrote: A table without names displays like a vector: unname(table(2:3)) [1] 1 1 1 and preserves the table class (as with unname in general): dput(unname(table(2:3))) structure(c(1L, 1L), .Dim = 2L, class = table) Does that make sense? R is not consistent in its treatment of such unname'd tables: DM One of the complaints about the S3 object system is that DM anything can claim to be of class foo, even if it DM doesn't have the right structure so that foo methods DM work for it. I think that's all you're seeing here: DM you've got something that is mislabelled as being of DM class table. The solution is don't do that. indeed! In plot, they are considered erroneous input: plot(unname(table(2:3))) Error in xy.coords(x, y, xlabel, ylabel, log) : 'x' and 'y' lengths differ but in melt, they act as though they have names 1:n: melt(unname(table(2:3))) indicies value 1 1 1 2 2 1 (By the way, is the spelling error built into too much code to be corrected?) -s PS What is the standard way of extracting just the underlying vector? c(unname(...)) works -- is that what is recommended? DM I would use as.numeric(), but I don't claim it's DM standard. many months ago in a discussion about the use (and misuse) of c() for coercing arrays/matrices to (atomic) vectors, Brian Ripley I think advertized the use of as.vector() with which I strongly agree. as.vector() here has the additional advantage of *not* transforming integer into double. Martin Maechler, ETH Zurich __ R-help@r-project.org mailing list 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.
Re: [R] Tables without names
On Fri, Jun 12, 2009 at 6:09 AM, Duncan Murdoch murd...@stats.uwo.cawrote: On 11/06/2009 5:35 PM, Stavros Macrakis wrote: A table without names displays like a vector: unname(table(2:3)) [1] 1 1 1 and preserves the table class (as with unname in general): dput(unname(table(2:3))) structure(c(1L, 1L), .Dim = 2L, class = table) Does that make sense? R is not consistent in its treatment of such unname'd tables: One of the complaints about the S3 object system is that anything can claim to be of class foo, even if it doesn't have the right structure so that foo methods work for it. Yes, that is one of its flaws. More specifically, in this case, operations on S3 objects can change them from being valid to being invalid. I think that's all you're seeing here: you've got something that is mislabelled as being of class table. Yes. The solution is don't do that. Agreed! But it's not clear to me how unname can *know* how not to do that in the general case. After all, unname on a vector of POSIXct's leaves a valid POSIXct object. ... PS What is the standard way of extracting just the underlying vector? c(unname(...)) works -- is that what is recommended? I would use as.numeric(), but I don't claim it's standard. Makes sense, as does the suggestion as.vector. So I guess the summary of 'stripping' operations is: c --- strip all attributes (including most but not all classes) except for names unname -- strip name attributes, but no other attributes (including class) unclass -- strip only class attribute as.vector -- strip all attributes including class and name; convert generic vectors to atomic vectors Am I missing others? -s [[alternative HTML version deleted]] __ R-help@r-project.org mailing list 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.
Re: [R] Tables without names
On Fri, Jun 12, 2009 at 10:57 AM, Stavros Macrakismacra...@alum.mit.edu wrote: On Fri, Jun 12, 2009 at 6:09 AM, Duncan Murdoch murd...@stats.uwo.cawrote: On 11/06/2009 5:35 PM, Stavros Macrakis wrote: A table without names displays like a vector: unname(table(2:3)) [1] 1 1 1 and preserves the table class (as with unname in general): dput(unname(table(2:3))) structure(c(1L, 1L), .Dim = 2L, class = table) Does that make sense? R is not consistent in its treatment of such unname'd tables: One of the complaints about the S3 object system is that anything can claim to be of class foo, even if it doesn't have the right structure so that foo methods work for it. Yes, that is one of its flaws. More specifically, in this case, operations on S3 objects can change them from being valid to being invalid. I think that's all you're seeing here: you've got something that is mislabelled as being of class table. Yes. The solution is don't do that. Agreed! But it's not clear to me how unname can *know* how not to do that in the general case. After all, unname on a vector of POSIXct's leaves a valid POSIXct object. ... PS What is the standard way of extracting just the underlying vector? c(unname(...)) works -- is that what is recommended? I would use as.numeric(), but I don't claim it's standard. Makes sense, as does the suggestion as.vector. So I guess the summary of 'stripping' operations is: c --- strip all attributes (including most but not all classes) except for names unname -- strip name attributes, but no other attributes (including class) unclass -- strip only class attribute as.vector -- strip all attributes including class and name; convert generic vectors to atomic vectors Am I missing others? There is also unlist. Also c and unlist are generic so their action can depend on the class of their argument. __ R-help@r-project.org mailing list 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.
[R] Tables without names
A table without names displays like a vector: unname(table(2:3)) [1] 1 1 1 and preserves the table class (as with unname in general): dput(unname(table(2:3))) structure(c(1L, 1L), .Dim = 2L, class = table) Does that make sense? R is not consistent in its treatment of such unname'd tables: In plot, they are considered erroneous input: plot(unname(table(2:3))) Error in xy.coords(x, y, xlabel, ylabel, log) : 'x' and 'y' lengths differ but in melt, they act as though they have names 1:n: melt(unname(table(2:3))) indicies value 11 1 22 1 (By the way, is the spelling error built into too much code to be corrected?) -s PS What is the standard way of extracting just the underlying vector? c(unname(...)) works -- is that what is recommended? [[alternative HTML version deleted]] __ R-help@r-project.org mailing list 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.
Re: [R] Tables without names
On Jun 11, 2009, at 5:35 PM, Stavros Macrakis wrote: A table without names displays like a vector: unname(table(2:3)) [1] 1 1 1 and preserves the table class (as with unname in general): dput(unname(table(2:3))) structure(c(1L, 1L), .Dim = 2L, class = table) Does that make sense? R is not consistent in its treatment of such unname'd tables: In plot, they are considered erroneous input: plot(unname(table(2:3))) Error in xy.coords(x, y, xlabel, ylabel, log) : 'x' and 'y' lengths differ but in melt, they act as though they have names 1:n: melt(unname(table(2:3))) indicies value 11 1 22 1 (By the way, is the spelling error built into too much code to be corrected?) -s PS What is the standard way of extracting just the underlying vector? c(unname(...)) works -- is that what is recommended? I think of R (contingency) tables as just integer arrays with attitude ... er, attributes. tt - table(c(1,1,1,3,3,3,5,5)) is.array(tt) [1] TRUE is.matrix( with(warpbreaks, table(wool, tension)) ) [1] TRUE So what would you do with a matrix that had row or column names? -- David Winsemius, MD Heritage Laboratories West Hartford, CT __ R-help@r-project.org mailing list 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.
