similar to: row.names(), rownames(), colnames(), names() ...?

Data frames are lists of columns. The names() function is appropriate for lists. It doesn't pay to fall into the trap of thinking that data frames are truly symmetric between columns and rows, because there is a performance penalty for accessing rows that is greater than the cost of accessing columns. With that in mind, thinking of data frames as lists is preferred, so names is preferred

There's a bit of a symmetry issue, which may or may not be important (led to 15 seconds of confusion until I got my bearings straight): row.names, rownames; colnames, no col.names? I _NOW_ realize the difference between row.names and rownames, but is there any reason not to have col.names for re-naming columns in a data.frame? (if there is, I don't particular need to know it, but it

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

Hi all I was wondering whether there has ever been an update on the rownames and colnames behaviour as described by Eric below? I still get the same behaviour, exactly as described by Eric, on my WinXP installation of R-2.3.0. I also posted a message to r-help on Friday but looking through the online archives it seems to have not made it to the list. I would agree with Eric that a consistent

Hi, I am working on some microarray data, and have some problems with writing iterations. In essence, the problem is that objects with three dimensions don't have rownames and colnames. These colnames and rownames would otherwise still be there in 2 dimensional objects. I need to generate multiple iterations of a 2 means-clustering algorithm, and these objects thus probably need 3

Looking into several different parts of R../src/library/base/R/*.R has led me to the conclusion that quite a bit of code doubling could be saved by using the following two functions whose naming philosophy is derived from that of NROW() & NCOL(): COLNAMES <- function(x) if(is.null(n <- colnames(x))) paste(seq(length=NCOL(x))) else n ROWNAMES <- function(x)

myDF <- data.frame(a = c("<0.1", NA, 0.3, 5, "Nil"), b = c("<0.1", 1, 0.3, 5, "Nil"), stringsAsFactors = FALSE) # you can subset the b-column in several ways myDF[ , 2] myDF[ , "b"] myDF$b # using the column, you make a logical vector ! is.na(as.numeric(myDF$b)) # This can be used to select the

Always via logical expressions. In this case you can use the logical expression myDF$b != "0" to give you a vector of TRUE/FALSE B. > On Sep 25, 2017, at 8:00 AM, Shane Carey <careyshan at gmail.com> wrote: > > This is super, really helpfull. Sorry, one final question, lets say I wanted to remove 0's rather than NAs , what would it be? > > Thanks >

I responded to the unhelpful suggestion "Why don't you implement and uplad the package to CRAN?" No mention of a search engine. Is this what you are commenting on Jeff? > On Jun 28, 2017, at 5:41 AM, Jeff Newmiller <jdnewmil at dcn.davis.ca.us> wrote: > > In what way does reminding people that packages exist because others just like them contributed something

I have noticed that when I iterate permutations of short vectors with the same seed, the cycle lengths are much shorter than I would expect by chance. For example: X <- 1:10 Xorig <- X start <- 112358 N <- 10 for (i in 1:N) { seed <- start + i for (j in 1:1000) { # Maximum cycle length to consider set.seed(seed) # Re-seed RNG to same initial state X <- sample(X)

No. The empty sum is zero. Adding it to another sum should not change it. Nothing audacious about that. This is consistent; other definitions just cause trouble. -pd > On 21 Mar 2018, at 18:05 , Boris Steipe <boris.steipe at utoronto.ca> wrote: > > Surely the result of summation of non-existent values is not defined, is it not? And since the NA values have been _removed_,

Super, Thanks On Fri, Sep 22, 2017 at 4:57 PM, Boris Steipe <boris.steipe at utoronto.ca> wrote: > > a <- c("<0.1", NA, 0.3, 5, "Nil") > > a > [1] "<0.1" NA "0.3" "5" "Nil" > > > b <- as.numeric(a) > Warning message: > NAs introduced by coercion > > b > [1] NA NA 0.3

ChatGPT-4: ------ Query: ---------------------------------- Thank you. The `value` in the code example is 2874. The plot shows a large number at the center and a smaller value computed as a delta relative to the `reference` of 4800. But the large value is given as 2870, and the smaller value is given as -1930 i.e. both values are rounded. Can I control the precision of these two numbers?

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'

This is super, really helpfull. Sorry, one final question, lets say I wanted to remove 0's rather than NAs , what would it be? Thanks On Mon, Sep 25, 2017 at 12:41 PM, Boris Steipe <boris.steipe at utoronto.ca> wrote: > myDF <- data.frame(a = c("<0.1", NA, 0.3, 5, "Nil"), > b = c("<0.1", 1, 0.3, 5, "Nil"), >

Please keep messages on the list so others can pitch in. _Which_ words do you want to consider identical for the purpose of frequency count? _What_ do you want to plot? B. > On Aug 3, 2017, at 4:36 PM, Riaan Van Der Walt <Riaan.VanDerWalt at nwu.ac.za> wrote: > > Hallo Boris, > I've loaded the Rstem, Snowball. > But I am clueless how to get a list eg. whal* (whale,

The loop : AllMAFs <- list() for (i in length(SeparatedGroupsofmealsCombs) { AllMAFs[[i]] <- apply( SeparatedGroupsofmealsCombs[[i]], 2, function(x)maf( tabulate( x+1) )) } gives these errors (I tried this many times and I'm sure I copied it entirely) :- Error in apply(SeparatedGroupsofmealsCombs[[i]], 2, function(x) maf(tabulate(x + : object 'i' not found > }

Although the loop seems to be formulated correctly I wonder why it gives me these errors : -object 'i' not found - unexpected '}' in "}" the desired output is expected to be very large as for each dataframe in the list of dataframes I expect to see maf value for each of the 600 columns! and this is only for for one dataframe in the list .. I have around 150-200

Hi all, How get colnames and rownames in Rcpp method? attecthed file : RGui.exe capture my work environment : R version : 2.11.1 OS : WinXP Pro sp3 Thanks and best regards. Young-Ju, Park from Korea [1][rKWLzcpt.zNp8gmPEwGJCA00] [@from=dllmain&rcpt=r%2Dhelp%40r%2Dproject%2Eorg&msgid=%3C20100728211143%2EH