similar to: converting matrix of lists to a regular matrix

Hello, I have a list with n numerical components of different length (3, 4 or 5 values in each component of the list); I need to export this as a text file where each component of the list will be a row and where missing values should fill in the blanks due to the different lengths of the components of the list. I think that as a first step I should convert my list to a data frame, but this is

I've searched for the answer to this in the help list archive, but wasn't able to get the answer to work. I'm interested in converting a row of a data.frame into a vector. However, when I use as.vector(x,[1,]) I get another data.frame, instead of a vector. (On the other hand, when I use as.vector(x,[,1]), I get a vector.) Thanks, Andrew [[alternative HTML version deleted]]

Hi We have touched on this before, but I don't think I quite got it right. So I have a list, each element of which is a a vector of 2 numbers: > l2 $cat000_a01 [1] 0.3429944 4.5138244 $cat000_a02 [1] 0.1929336 4.3064944 $cat000_a03 [1] -0.2607796 4.1551591 What I actually want to convert this into is a matrix with the names (cat000_a01 etc) as row names, the first element of each of

Hi. Can anyone suggest a simple way to re-sort in R a list of vectors of the following form? input $"1" a b c 1 2 3 $"2" a b c 4 5 6 Output should be something like: "a" "1" 1 "2" 4 "b" "1" 2 "2" 5 "c" "1" 3 "2" 6 I've been futzing with mapply(), outer(), split(), rbind()

I'm trying to find a more elegant way of doing this. What I'm trying to accomplish is to count the frequency of letters (major / minor alleles) in a string grouped by the factor levels in another column of my data frame. Ex. > DF<-data.frame(c("CC", "CC", NA, "CG", "GG", "GC"), c("L", "U", "L",

Dear all, I have dataset x <- list(matrix(1:20, 5, 4),matrix(1:20, 5, 4),matrix(1:20, 5, 4)) y <- list(matrix(110:114, 5, 1),matrix(110:114, 5, 1),matrix(110:114, 5, 1)) I need merge x and y as list (y put in last column). The result is something like [[1]] [,1] [,2] [,3] [,4] [,5] [1,] 1 6 11 16 110 [2,] 2 7 12 17 111 [3,] 3 8 13 18 112 [4,] 4

I have a very large dataframe and wish to extract a subset of rows. I have a two column matrix listing the starting and ending indices of one subset on each row. My idea is to create a vector of indices that could be applied to the dataframe and I have a solution using a for loop (below). But surely there is some more elegant way to do this! I looked thorough the archives without

Dear R people, I have to deal with the output of a function which comes as a matrix of vectors. You can reproduce the structure as given below: x <- list(c(1,2,4),c(1,3,5),c(0,1,0), c(1,3,6,5),c(3,4,4,4),c(0,1,0,1), c(3,7),c(1,2),c(0,1)) data <- matrix(x,byrow=TRUE,nrow=3) colnames(data) <- c("First", "Length", "Value") rownames(data)

Hi Sorry to ask such a basic question. I have a list, each element of which is a vector of two values. What I actually want is a matrix with two columns, and one row per element of the list. Obviously I have tried as.matrix(), and as.vector() but I didn't expect the latter to work. I feel so lame asking this. Any suggestions? Mick

In the following code, I'd like to be able to create a new variable containing the value of the names of the list. a <- data.frame(var.1 = 1:5) b <- data.frame(var.1 = 11:15) test.list <- list(a=a, b=b) # in this case, names(test.list) is "a" and "b" # and I'd like to use lapply() so that # I get something that looks like # var.1 var.2 # 1 a # 2

A couple days ago, Mark Leeds asked about a solution that would basically stagger two lists, a and b, to return a list in the form of a[1], b[1], a[2], b[2], a[3].... In particular, the summary of his question was in reference to lists defined by x <- 5 tempin <- seq(1,1411, by=30) a <- tempin b <- tempin + x I offered the following function everyOther <-

I've been doing some consulting with students who seem to come to R from SAS. They are usually pre-occupied with do loops and it is tough to persuade them to trust R lists rather than keeping 100s of named matrices floating around. Often it happens that there is a list with lots of matrices or data frames in it and we need to "stack those together". I thought it would be a simple

Folks: In answer to a query, Andy Liaw recently submitted some code to construct a block diagonal matrix. For what seemed a fairly straightforward task, the code seemed a little "overweight" to me (that's an American stock analyst's term, btw), so I came up with a slightly cleaner version (with help from Andy): bdiag<-function(...){ mlist<-list(...) ## handle case in

Hello, I am working on some examples of GLMM for my students but I am afraid that my way of preparing a dataframe to pass to lmer will make them think that R is a very difficult and un-natural language. Here is for example a simple data set about approval ratings on two different surveys for a random sample of 1600 individuals. > ## Example: Ratings of prime minister (Agresti, Table 12.1,

Dear R-users This seems to be a trivial problem but at the moment I don?t know how to solve it. I have a list with 7000 matrices, every matrix has 2 columns but different row-sizes. Now I want to combine all lists into one matrix with 2 columns. I would have to write: ma <- rbind(list[[1]],list[[2]], and so on) (this works fine for lists with few matrices) Since it is not possible to write:

Hello, I am trying to convert BY to a data frame, consider the following example: exampleDF<-data.frame(a=c(1,2),b=c(10,20),name=c("first","second")) exampleBY<-by(exampleDF,with(exampleDF,paste(a,b,sep="_")),               function(x) {                 data.frame(                     name=as.character(x$name),                     a=x$a,                    

Hi all, I would greatly appreciate some help understanding how R references arrays, matrices, lists, and objects using [[]] and []. I have read the R guides and several tutorials but I am not the fastest kid on the block so I am still having difficulty understanding this. For examples the following code produces a 5 element list of 2X5 random numbers that I then convert to a 2X5X5 matrix.

Hi, I have a long list of lists from which I want to efficiently extract and rbind elements. So I'm using the approach below: f <- function(i){ out <- replicate(5, list(matrix(rnorm(80), nc=20))) names(out) <- letters[1:5] out } set.seed(1) lst <- lapply(1:1.5e6, f) (t0 <- system.time(tmp <- do.call(rbind, lapply(lst, '[[', 'b')))) Is there

>>>>> David L Carlson <dcarlson at tamu.edu> >>>>> on Wed, 2 May 2018 21:43:52 +0000 writes: > Typo: dat[[z]] should be x[[z]]: > > x2 <- do.call(rbind, lapply(names(x), function(z) > data.frame(type=z, x[[z]]))) > x2 > type x y > 1 A 1 3 > 2 A 2 4 > 3 B 5 7 > 4 B 6 8 > >

Is there an efficient way to use rbind() with the five dataframes described in the following example: a <- c(1:5) list.foo <- lapply(a, function(x) data.frame(beta=a*rnorm(10), deta=a*rnorm(10))) big.data.frame <- rbind(list.foo[[1]], list.foo[[2]], list.foo[[3]], list.foo[[4]], list.foo[[5]]) #is there an easier method? For example, I naively thought you could do something like