similar to: Subsetting a list of vectors

Displaying 20 results from an estimated 40000 matches similar to: "Subsetting a list of vectors"

2003 Dec 02
8
Vector Assignments
Hi, I have simple R question. I have a vector x that contains real numbers. I would like to create another vector col that is the same length of x such that: if x[i] < 250 then col[i] = "red" else if x[i] < 500 then col[i] = "blue" else if x[i] < 750 then col[i] = "green" else col[i] = "black" for all i I am convinced that there is probably a
2010 Dec 07
5
fast subsetting of lists in lists
Hello, my data is contained in nested lists (which seems not necessarily to be the best approach). What I need is a fast way to get subsets from the data. An example: test <- list(list(a = 1, b = 2, c = 3), list(a = 4, b = 5, c = 6), list(a = 7, b = 8, c = 9)) Now I would like to have all values in the named variables "a", that is the vector c(1, 4, 7). The best I could come up
2010 Aug 24
2
Comparing/diffing strings
Hi all, all.equal is generally very useful when you want to find the differences between two objects. It breaks down however, when you have two long strings to compare: > all.equal(a, b) [1] "1 string mismatch" Does any one know of any good text diffing tools implemented in R? Thanks, Hadley -- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice
2018 Jun 08
3
Subsetting the "ROW"s of an object
> On Jun 8, 2018, at 1:49 PM, Hadley Wickham <h.wickham at gmail.com> wrote: > > Hmmm, yes, there must be some special case in the C code to avoid > recycling a length-1 logical vector: Here is a version that (I think) handles Herve's issue of arrays having one or more 0 dimensions. subset_ROW <- function(x,i) { dims <- dim(x) index_list <-
2010 Feb 04
4
Why is there no c.factor?
Hi all, Is there are reason that there is no c.factor method? Analogous to c.Date, I'd expect something like the following to be useful: c.factor <- function(...) { factors <- list(...) levels <- unique(unlist(lapply(factors, levels))) char <- unlist(lapply(factors, as.character)) factor(char, levels = levels) } c(factor("a"), factor("b"),
2018 Jun 08
6
Subsetting the "ROW"s of an object
Hi all, Is there a better to way to subset the ROWs (in the sense of NROW) of an vector, matrix, data frame or array than this? subset_ROW <- function(x, i) { nd <- length(dim(x)) if (nd <= 1L) { x[i] } else { dims <- rep(list(quote(expr = )), nd - 1L) do.call(`[`, c(list(quote(x), quote(i)), dims, list(drop = FALSE))) } } subset_ROW(1:10, 4:6) #> [1] 4 5 6
2004 Dec 24
6
Sorting problem
Hi I'm using R 2.0 in SuSE 9.2. When I plot data as a boxplot, the boxes appear on the plot in alphabetical order (of group) rather than the order in which they appear in the data. So far, the only thing I can do to fix this is to prefix the group labels with a,b,c...etc to trick R into plotting them in the right order. Can sorting be turned off? How should I address this sensibly? Thanks
2005 Dec 26
1
Seg fault with trace
(Under 2.2.0, Mac) I have been unable to reduce this to a simple case, so I'll include my full code, and my intentions. The problem I'm trying to solve is that while many defaults (eg. na.rm=F, drop=T) make sense for interactive programming, they tend to be a bit of a pain when developing a package. For example, I often forget to use drop=FALSE, only test with multiple columns and then
2018 Jun 08
2
Subsetting the "ROW"s of an object
I suspect this will have suboptimal performance since the TRUEs will get recycled. (Maybe there is, or could be, ALTREP, support for recycling) Hadley On Fri, Jun 8, 2018 at 10:16 AM, Berry, Charles <ccberry at ucsd.edu> wrote: > > >> On Jun 8, 2018, at 8:45 AM, Hadley Wickham <h.wickham at gmail.com> wrote: >> >> Hi all, >> >> Is there a better to
2018 Jun 08
4
Subsetting the "ROW"s of an object
> On Jun 8, 2018, at 11:52 AM, Hadley Wickham <h.wickham at gmail.com> wrote: > > On Fri, Jun 8, 2018 at 11:38 AM, Berry, Charles <ccberry at ucsd.edu> wrote: >> >> >>> On Jun 8, 2018, at 10:37 AM, Herv? Pag?s <hpages at fredhutch.org> wrote: >>> >>> Also the TRUEs cause problems if some dimensions are 0: >>>
2007 Dec 19
3
Obtaining replicates numbers of a vector
Dear R-help, I am trying to have a generic way to assess the replicates in a character vector. Say that I have the following vector: x <- c('A','B','A','C','C','B') I would like to obtain: replicates <- c(1,1,2,1,2,2) each number beeing the time we see the corresponding value in x. Any clever and generic way to obtain that? Eric --
2018 Jun 08
3
Subsetting the "ROW"s of an object
> On Jun 8, 2018, at 10:37 AM, Herv? Pag?s <hpages at fredhutch.org> wrote: > > Also the TRUEs cause problems if some dimensions are 0: > > > matrix(raw(0), nrow=5, ncol=0)[1:3 , TRUE] > Error in matrix(raw(0), nrow = 5, ncol = 0)[1:3, TRUE] : > (subscript) logical subscript too long OK. But this is easy enough to handle. > > H. > > On
2011 Oct 05
1
Vector-subsetting with ZERO - Is behavior changeable?
Dear All, I have trouble generizising some code. > index <- 0 > sapply(list(c(1,2,3),c(1,2),c(1)),function(x){x[max(length(x)-index,0)]}) Will yield a wished for vector like so: [1] 3 2 1 But in this case (trying to select te second to last element in each vector of the list) > index <- 1 > sapply(list(c(1,2,3),c(1,2),c(1)),function(x){x[max(length(x)-index,0)]}) I end up
2010 Mar 19
5
Encrypt/decrypt in R
Hi all, Does any one know of any encryption/decryption algorithms in R? I'm not looking for anything robust - I want some way of printing output to the screen that the user can't read immediately, but can decrypt a little later. The main thing I don't want to the user to see is a number, so (e.g.) ROT13 isn't appropriate. Hadley -- Assistant Professor / Dobelman Family Junior
2004 Apr 05
3
Evaluation of functionals
Suppose I have f1 <- function(x) x f2 <- function(x) x^2 funlist <- list(f1,f2) Then I would like to evaluate funlist such that when x is 10 I should get a list with 10 and 100. A naive way of doint this is myf <- funlist[[1]] do.call(paste(quote(myf)), list(x=10)) myf <- funlist[[2]] do.call(paste(quote(myf)), list(x=10)) - but there has to be much
2008 Apr 12
4
HOW TO AVOID LOOPS
> Looking for a simple, effective a minimum execution time solution. > > For a vector as: > > c(0,0,1,0,1,1,1,0,0,1,1,0,1,0,1,1,1,1,1,1) > To transform it to the following vector without using any loops: > (0,0,1,0,1,2,3,0,0,1,2,0,1,0,1,2,3,4,5,6) > Appreciate any suggetions. [[alternative HTML version deleted]]
2007 Dec 09
1
List comprehensions for R
Below is code that introduces a list comprehension syntax into R, allowing expressions like: > .[ sin(x) ~ x <- (0:11)/11 ] [1] 0.00000000 0.09078392 0.18081808 0.26935891 0.35567516 0.43905397 [7] 0.51880673 0.59427479 0.66483486 0.72990422 0.78894546 0.84147098 > .[ .[x*y ~ x <- 0:3] ~ y <- 0:4] [,1] [,2] [,3] [,4] [,5] [1,] 0 0 0 0 0 [2,] 0 1 2
2008 Oct 15
3
request: How can we ignore a component of list having no element
Dear friends There is a list of arrays comprising different no of rows and columns even sometimes NULL, such as [[2]] given below. How can we ignore [[2]] or others like this in the complete list. Any help in this regard is needed. Thanks [[1]] [,1] [,2] [1,] 3 1 [2,] 3 1 [3,] 3 1 [[2]] NULL [[3]] [,1] [,2] [,3] [,4] [,5] [,6] [,7] [1,] 3 1
2018 Jun 08
1
Subsetting the "ROW"s of an object
On 06/08/2018 10:15 AM, Michael Lawrence wrote: > There probably should be an abstraction for this. In S4Vectors, we > have extractROWS(). FWIW the code in S4Vectors that does what your subset_ROW() does is: https://github.com/Bioconductor/S4Vectors/blob/04cc9516af986b30445e99fd1337f13321b7b4f6/R/subsetting-utils.R#L466-L476 (This is the default "extractROWS" method.) Except
2006 Jun 23
1
How to use mle or similar with integrate?
Hi I have the following formula (I hope it is clear - if no, I can try to do better the next time) h(x, a, b) = integral(0 to pi/2) ( ( integral(D/sin(alpha) to Inf) ( ( f(x, a, b) ) dx ) dalpha ) and I want to do an mle with it. I know how to use mle() and I also know about integrate(). My problem is to give the parameter values a and b to the