similar to: with lapply() how can you retrieve the name of the object

Hello. I'm using as.ffdf(mydataframe) to create ffdf objects inside an lapply loop and returning that. I then use crbind to combine the lapply results into allData. So...simplified flow looks like this. res <- lapply(1:nchunks, function(n) { blah blah with nth chunk mydataframe <- data.frame(blah blah) dat <-

Dear list members, I am trying, within a lapply command, to print the name of the objects in list or data frame. This is so that I can use odfWeave to print out a report with a section for each object, including the object names. I tried e.g. a=b=c=1:5 lis=data.frame(a,b,c) lapply( lis, function (z) { obj.nam <- deparse(substitute(z)) cat("some other text",obj.nam,"and so

Hi all! I'm afraid I programmed something totally non-sensical and inefficient, but I can't figure out how to do it better. I have a list of ~ 40 000 characters. I want to take each element at a time, map it to a large data frame with hit=which(data.frame$column==elementFromList), then compute some statistic on data.frame[hit,] and return a result that consists of either 1) a list

Dear folks: Let?s suppose I want a function to print return the name of the object passed to it. > myname <- function(object) {out<-deparse(substitute(object)); out} This works fine on a single object: > O1 <-c(1:4) > myname(O1) [1] "O1" However it does not work if you use lapply to pass it the same object from a list: > O2 <-c(1:4) > object.list <-

Take the following code: foo <- list() foo[[1]] <- list(a=1, b=2) foo[[2]] <- list(a=11, b=22) foo[[3]] <- list(a=111, b=222) result <- do.call(rbind, foo) result[,'a'] In this case, result[,'a'] shows a list. Is there a more elegant way such that result is a "regular" matrix of vectors? I imagine there are manual ways of going about this, but I was

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 <-

Hi everyone, I have dataset which I make a sample of it couple of times and each time I get the mean and standard deviation of each row for each sample. I have a function for that, which takes the name of the file and number of times to sample and then returns the mean and standard deviation for each row in each sample. Sample=function(name, n){

Dear All, to produce output of several columns of a data frame, I tried to use lapply and also l_ply. In both cases, I would like to print a header line containing also the name of the respective column in the data frame. For example, I would like the following lapply(data.frame(a=1:3, b=2:4), function(x) print(deparse(substitute(x)))) to produce: [1] "a" [1] "b" and

Hi there, I have a very simple question. If I execute the following code: test <- function(x) { name <- paste(x,"info_within_function") c(1,2,3,4,5) } ret <- lapply(1:10, test) , I end up with a list and each entry is just numbered [[1]], [[2]], ... [[10]] How can I force the result entries gettings names which are determined within the function. For this example,

Hello, I'm having difficulty passing an object name to a lapply function. Can somebody tell me the trick to make this work? #Works T13702 <- TRACKDATA[["13702.xls"]][["data"]] min(unlist(lapply(list(T13702), function(x) mdy.date(x[1, 2], x[1, 1], x[1, 3])))) 16553 #Works d<-2 assign(paste("T",substr(names(TRACKDATA)[d],1,(nchar(names(TRACKDATA)[d]

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

Dear list, I have a list of matrices : i1 <- matrix(1:10, nrow = 2, ncol = 5) i2 <- matrix(11:20, nrow = 2, ncol = 5) j <- list(i1 = i1, i2 = i2) I would like to attribute names to each dimension, for each matrix, as follows : $i1 B1 B2 B3 B4 B5 A1 1 3 5 7 9 A2 2 4 6 8 10 $i2 B1 B2 B3 B4 B5 A1 11 13 15 17 19 A2 12 14 16 18 20 However, I have to use lapply function and attribute

Hello everyone, I wonder if there is a way to pass the index or name of a list to a user-specified function in lapply(). For instance, my desired effect is something like the output of > L <- list(jack=4098,sape=4139) > lapply(seq(along=L),function(i,x) if(i==1) "jack" else "sape",x=L) [[1]] [1] "jack" [[2]] [1] "sape" >

Hi. I have a list where each object in the list has multiple parts. I'd like to take the mean of just one part of each object. Is it possible to do this with lapply? If not, can you recommend another function? Thanks. eric > x1 <- c(0,1,2,3) > x2 <- c(7,8) > x3 <- c(2,6,6,8) > x4 <- c(4,8) > > Lst1 <- list(label1 = x1,label2 = x2) > Lst2 <-

Hello, I'm writing a program that takes a tree in input (nested lists) and returns a copy of it replacing the leaves with something else (eg: a computation done on the original leaves). In the example below, the tree is composed by countries and cities, and the leaves (children of the cities) are vectors of numbers. The program takes this tree and replaces the vectors at the bottom by their

My data looks like this: > data name G_hat_0_0 G_hat_1_0 G_hat_2_0 G_0 G_hat_0_1 G_hat_1_1 G_hat_2_1 G_1 1 rs0 0.488000 0.448625 0.063375 1 0.480875 0.454500 0.064625 1 2 rs1 0.002375 0.955375 0.042250 1 0.000000 0.062875 0.937125 2 3 rs2 0.050375 0.835875 0.113750 1 0.877250 0.115875 0.006875 0 4 rs3 0.000000 0.074750 0.925250 2 0.897750 0.102000

Happy New Year, all! I want to do calculations on each element of a list l, but i want the returned list element to be named differently after the calculation. Is it possible to do the renaming somehow within the lapply call? l <- list(a=NA, b=NA) lapply(l, function(x) {names(x) <- "new name"; return(x) }) This does not work, any ideas? TIA

Hi, #working directory data1 #changed name data to data1.? Added some files in each of sub directories a1, a2, etc. ?indx1<- indx[indx!=""] lapply(indx1,function(x) list.files(x)) #[[1]] #[1] "a1.txt"??????? "mmmmm11kk.txt" #[[2]] #[1] "a2.txt"??????? "mmmmm11kk.txt" #[[3]] #[1] "a3.txt"??????? "mmmmm11kk.txt" #[[4]] #[1]

> a <- sqlQuery(irrdb, "select count(field) from mytable where field = 1") > print(a) count(field) 1 8 > paste(a) [1] "as.integer(8)" Why the as.integer() representation? I later pass the result into this write.html.table(), and what I get is rows of as.integer()... when all I want is the integer itself. as.integer(31) as.integer(21)

Hi, Please dput() your example dataset. dat1<- read.table(text="a?? a?? a?? a??? a??? b?? b??? b??? c??? c?? c??? c 2? 4??? 5?? 2??? 7??? 2?? 2??? 6??? 3??? 7?? 9??? 3 3? 3?? 4?? 1???? 6??? 8?? 1??? 3??? 5??? 2??? 6??? 3",sep="",header=FALSE,stringsAsFactors=FALSE) library(reshape) ?dat2<-melt(as.data.frame(t(dat1)),id.var="V1")[,-2]