similar to: Error with lapply

Hi, I have created a list object like that : x = vector("list") for (i in 1:5) x[[i]] = rnorm(2) x Now I want to do two things : 1. for each i, I want to do following matrix calculation : t(x[[i]]) %*% x[[i]] i.e. for each i, I want to get a 2x2 matrix 2. Next I want to get x[[1]] + x[[2]] +.... I did following : res=vector("list"); res = sapply(x, function(i) t(x[[i]]) %*%

[My previous message rejected, therefore I am sending same one with some modification] I have 3 vectors with object name : dat1, dat2, dat3 Now I want to create a loop, like : for (i in 1:3) { cat(sd(dati)) } How I can do this in R? Regards,

Dear all, Trying to extract a few rows for each element of a list of data.frames, I'm puzzled by the following behaviour, > d <- lapply(1:4, function(i) data.frame(x=rnorm(5), y=rnorm(5))) > str(d) > > lapply(d, "[", i= c(1)) # fine, this extracts the first columns > lapply(d, "[", j= c(1, 3)) # doesn't do nothing ?! > > library(plyr)

Dear all, Trying to extract a few rows for each element of a list of data.frames, I'm puzzled by the following behaviour, > d <- lapply(1:4, function(i) data.frame(x=rnorm(5), y=rnorm(5))) > str(d) > > lapply(d, "[", i= c(1)) # fine, this extracts the first columns > lapply(d, "[", j= c(1, 3)) # doesn't do nothing ?! > > library(plyr)

Dear falks, here I have written following function :   fn <- Vectorize(function(x = 1:3, y = 3:6) {         x <- matrix(x, nrow=1)         y <- matrix(y, ncol=1)         dat <- apply(x, 2, function(xx) {                               apply(y, 1, function(yy) {                                   return(xx + yy) } ) })         return(dat)}, SIMPLIFY = TRUE) If I run this function, I got

Dear all, I am looking for some procedure to apply 'ifelse' condition on function. I have created an alternative to lapply() function with exactly same set of arguments named lapply1(), however with different internal codes. Therefore I want something like, if (some condition) then call lapply1() otherwise lapply() function. Ofcourse I can create a complete if()... else()... like of

Sometimes I'm iterating over a list where names are keys into another data structure, e.g. a related list. Then I can't use lapply as it does [[]] and loses the name. Then I do something like this: do.one <- function(ldf) { # list-dataframe item key <- names(ldf) meat <- ldf[[1]] mydf <- some.df[[key]] # related data structure r.df <-

Dear all, I have following kind of character vector: Vec <- c("344426", "dwjjsgcj", "123sgdc", "aagha123", "sdh343asgh", "123jhd51") Now I want to split each element of this vector according to?numeric?and string element. For example in the 1st element of that vector, there is no string element. Therefore I should get a vector of

Hello everybody, I have problem with a lapply command, which rather proves that I don't fully understand it. I want to extract from a list that consists of dataframes, the length of the first sequences from a given variable (its part of a simulation exercises). Below is code which does the job, but I think it should be possible to make it more compact. ### Example Data dat <-list()

Hi, is there any way to say: "this class 'x' is a S3 class?" For example what is the type of class "data.frame"? Is it a S3 class or S4? How can I get a complete list of all S3 classes currently available? Thanks,

[I am really sorry if it is double posted, I doubt me previous post could not reach forum due to some problem with net] Suppose I have a matrix : a = matrix(1:9, 3) >From this matrix, I construct 9 additional matrices : i = 1:9 bi = a * i Now combining all those 9 new matrices, I construct a final metrix as : c = b1 b4 b7 b2 b5 b8 b3 b6 b8 I want to automate this procedure for any

I've defined my own version of summary.default, that gives a better summary for highly skewed vectors. If I call summary(x) the method is used. If I call summary(data.frame(x)) the method is not used. I've traced this to lapply; this uses the new method: lapply(list(x), function(x) summary(x)) and this does not: lapply(list(x), summary) If I make a copy of lapply, WITHOUT the

Hi all, previously I submitted this thread through Nabble which seems fail therefore sending it again.... suppose I have written following function :  > fn = function(x) return(x+x^2)  > fn  function(x) return(x+x^2)  Here you see, if I type only the function name all inside information of this function are visible. Is there any way to protect them i.e. make them invisible?  Thanks

Can anyone please tell me how to define a "list". Suppose I want to define a list object "result" with length n then want to fill each place of "result" with different objects. For e.g. i=1 result[1] = rnorm(1) i=2 result[2] = rnorm(2) ....................... i=n result[n] = rnorm(n) What would be the best way to do that? Regards,

I want to create a number of vectors like : vec1 <- rnorm(1) vec2 <- rnorm(2) vec3 <- rnorm(3) and so on........... Here I tried following : for (i in 1:10) paste("vec", i, sep="") <- rnorm(i) However obviously that is not working. Here vectors I need to be seperated i.e I do not want to create a "list". How to modify above code? -- View this

I have 2 vecros : x<-c(100,96,88,100,100,96,80,68,92,96,88,92,68,84,84,88,72,88,72,88) x1 = sample(x, 5, replace=FALSE) Now i want to get remaining values of vector "x" those are not member of vector "x1". Can anyone please tell me how to do that?

Thanks David, It is working. Holtman's also gave me a solution but, I wanted to have a color pallet for description of colors, that was not in his solution. However I need one small modification. If I want to plot only lower diagonal elements of 'dat' then how should I proceed? What I want is, to visualize only lower diagonal elements and having the color pallet on them only. Also

Dear all R users, I have a small doubt about panel data analysis. My basic understanding on Panel data is a type of data that is collected over time and subjects. Vector Autoregressive Model (VAR) model used on this type of data. Therefore can I say that, one of statistical tools used for analysis of panel data is VAR model? If you clarify my doubt I will be very grateful. Thanks and regards,

Dear All, I have a following for-loop code which is basically intended to read in many excel files (each file has many columns and rows) in a directory and extract the some rows and columns out of each file and then combine them together into a dataframe. I use for loop which can do the work but quite slow. How to make it faster using lapply function ? Thanks in advance! temp.df<-c() #

Let me take an artifical matrix : dat = matrix(rnorm(200*200), 200, 200) My goal is to visualize this matrix according to the procedure, described in previous mails. I took Mendelssohn's advice and got following advice : ?plot.im Z <- setcov(owin()) plot(Z) .................... etc However I can not reproduce this example in my problem. How I can change my data