similar to: row.names in data.frame

Dear R-devel, Can anyone help me to understand this? It seems that subscripting the rows of a data.frame without actually changing their order, somehow changes an internal representation of row.names that is revealed by e.g. dput/dump/serialize I have read the docs and inspected the (R) code for data.frame, rownames, row.names and dput without enlightenment. df=data.frame(a=1:10, b=1)

On Thu, 30 Oct 2008, wdunlap at tibco.com wrote: > Full_Name: Bill Dunlap > Version: R version 2.9.0 Under development (unstable) (2008-10-29 r46795) > OS: Linux > Submission from: (NULL) (76.28.245.14) > > > When data.frame() is given a matrix with rownames, then the type of the output > row names depends on whether the first element of the input row names is ""

On Sun, 31 Dec 2000 jfox@mcmaster.ca wrote: > The editor in R version 1.2.0 returns an error after editing a data frame > that has row names. This is on a Windows 2000 system, but I've encountered > the same problem under Windows 95. Here's a simple example: Actually, that's not where the error is. If you use traceback() you will see it is in edit.data.frame. That tries

Full_Name: Bill Dunlap Version: R version 2.9.0 Under development (unstable) (2008-10-29 r46795) OS: Linux Submission from: (NULL) (76.28.245.14) When data.frame() is given a matrix with rownames, then the type of the output row names depends on whether the first element of the input row names is "" or not. The other elements of the input row names don't affect things. E.g.,

Dear all, Happy New Year for all of you! I hope we have an year of essential freedom for everyone! I am trying to manipulate a matrix in order to know in which column and in which row a number is allocated. But, when we use the function "which" it returns the position of the number in the "vector representation of the matrix". For example: >

I expected the row names to be unique but a data frame appears to be able to hold duplicate row names. This makes me thing that there must be circumstances when it is necessary. However, I cannot think of any. Please enlighten me. [[alternative HTML version deleted]]

[I think Doug Bates has already alluded to this, somewhere..] In R, data.frame( ... ) does not construct row.names whereas in S, it does: R: > data.frame(x=1:2,y=3:4) x y [1,] 1 3 [2,] 2 4 > row.names(data.frame(x=1:2,y=3:4)) NULL S-plus: > data.frame(x=1:2,y=3:4) x y 1 1 3 2 2 4 > row.names(data.frame(x=1:2,y=3:4)) [1] "1" "2"

Why does the following show a class attribute of "character" when using the interpreter: x <- data.frame(hat=1:10) class(rownames(x)) ## returns [1] "character" but when called from c/cpp, the rownames attribute has no class attribute, and is in fact a vector of INTSXP? > .Call("print_class_of_rownames", x, package = "test") length(x): 10

Hello, I'd like to report what I think is a bug: using as.data.frame() we can create duplicate row names in a data frame. R version 3.4.3 (current stable release). Rather than paste code in an email, please see the example formatted code here: https://stackoverflow.com/questions/49031523/duplicate-row-names-in-r-using-as-data-frame I posted to StackOverflow, and consensus was that we should

I want to use ActiveRecord outside of Rails to do processing on large tables. I want to be able to process the rows as they are retrieved rather than having to store the results in an intermediate array. Any suggestions? Looks like I could hack the adapter to provide an accessor to the underlying DBI handle. Anything cleaner than that?

I noticed something surprising (in R 2.2.1 on WinXP) According to the documentation, rownames and colnames are character vectors. Assigning a vector of class POSIXct or POSIXlt as rownames or colnames therefore is not strictly according to the rules. In some cases, R performs a reasonable typecast, but in some other cases where the same typecast also would be possible, it does not. Assigning a

I noticed something surprising (in R 2.2.1 on WinXP) According to the documentation, rownames and colnames are character vectors. Assigning a vector of class POSIXct or POSIXlt as rownames or colnames therefore is not strictly according to the rules. In some cases, R performs a reasonable typecast, but in some other cases where the same typecast also would be possible, it does not. Assigning a

Plugin location: http://svn.kylemaxwell.com/getdate_column/ ** Won''t work on Windows ** OVERVIEW =================== Getdate_column is designed to make the accessor methods of a datetime column accept and return string representations of the date (e.g. "today", "10 days from now", "1/2/06 10pm"). I personally find date controls on the web to be clumsy,

Hello, I have defined a new class > setClass("myclass", representation(min = "numeric", max = "numeric")) and want to write accessor functions, so that for > foo = new("myclass", min = 0, max = 1) > min(foo) # prints 0 > max(foo) # prints 1 At first i created a generic function for "min" > setGeneric("min",

Hi, I have a data.frame that looks something like this. feature 5637 ? ? ? ? ? ? ? ?1321N1 feature1 -0.568750616 -0.934748758 feature2 -0.913080902 -0.941455172 feature3 0.442477294 -0.257921866 I want to change it to look like this. feature ? ? ?cell.line ? ? value feature1 5637 -0.568750616 feature2 5637 -0.913080902 feature3 5637 0.442477294 feature1 1321N1

Hi all, Is there a function to extract row names from a data frame based on row names from another data frame? I can write a loop function to do this, but this may be inefficient in terms of processing. thanks for any information, Wade

I need to write a data frame along with its column and row names to a text file. However, the first row in the text file is always short of one element. I have tried setting different parameters to write.table but that didn't help. > m A B C 1 2 D 3 4 Using write.table(m, "table.xls", sep="\t", col.names=T, row.names=T) gives A B C 1 2 D 3 4

Relative noob here, I have a data.frame and simply want to add an explicit column of names in column 1 of the form "trial_number01" for row 1, "trial_number02" for row 2 .... etc. It is simply for visual purposes and to explain data to others. I've tried Using row.names and other but still no luck, am sure it has been covered but I can't find it, can you please point

Below x1, x2 and x3 all have the same data and all have the same value for row.names(x); however, the internal values of their row.names differ. The internal value of row.names is c(NA, -4L) for x1, c(NA, 4L) for x2 and c("1", "2", "3", "4") for x3; nevertheless, identical regards x1 and x2 as identical while x3 is not identical to either of x1 or x2. Is

With a recent R 2.4 I notice the following: df <- data.frame(x=1:2) > row.names(df) [1] "1" "2" > rownames(df) [1] 1 2 This seems related to recent changes in the internal storage format of the row names data for data frames. The man page for rownames says: For a data frame, 'rownames' and 'colnames' are equivalent to 'row.names'