similar to: Return list of data frames.

Displaying 20 results from an estimated 6000 matches similar to: "Return list of data frames."

2011 Jan 06
8
Accessing data via url
# Can anyone suggest why this works datafilename <- "http://personality-project.org/r/datasets/maps.mixx.epi.bfi.data" person.data <- read.table(datafilename,header=TRUE) # but this does not? dd <- "https://sites.google.com/site/jrkrideau/home/general-stores/trees.txt" treedata <- read.table(dd, header=TRUE)
2011 Jan 06
0
Problem with package twitteR and converting S4 obj to data frame
Hi, I wrote a simple script to retrieve an n number of followers for a given user in Twitter. I used a sample of n=10 to test my script and worked perfectly but once I started to changes n I started to get the following error: Error in list_to_dataframe(res, attr(.data, "split_labels")) : Results do not have equal lengths I have no clue why works fine with n=10 but for higher
2004 Nov 01
5
make apply() return a list
Hi, I have a dataframe (say myData) and want to get a list (say myList) that contains a matrix for each row of the dataframe myData. These matrices are calculated based on the corresponding row of myData. Using a for()-loop to do this is very slow. Thus, I tried to use apply(). However, afaik apply() does only return a list if the matrices have different dimensions, while my matrices have
2005 Sep 19
3
Lists and data frames (PR#8143)
Full_Name: Frank Wagner Version: R 2.1.1 OS: Windows Submission from: (NULL) (193.174.73.34) Hi, The pdf file R-intro descripe on page 27 that lists can be extended by adding numbers. Unfortunately, it's not working ## example : # if i did not declare the variable an error occurs : object not found mylist <- list() mylist[1] <- list(value1=3, value2=5) ## Error Can you please help
2015 May 04
2
Define replacement functions
Hello I tried to define replacement functions for the class "mylist". When I test them in an active R session, they work -- however, when I put them into a package, they don't. Why and how to fix? make_my_list <- function( x, y ) { return(structure(list(x, y, class="mylist"))) } mylist <- make_my_list(1:4, letters[3:7]) mylist mylist[['x']] <- 4:6
2010 Jan 30
2
parsing files for plot
Hi, I have many files containing one column of data. I like to use the scan function to parse the data. Next I like to bind to a large vector. I try this like: count<-1 files <- list.files() # all files in the working directory for(i in files) { tmp <- scan(i) assign(files[count], tmp) count<-count+1 } This part works! Now I like to plot the data in a boxplot.
2012 Jun 28
3
loop through and modify multiple data frames
Hi Newbie question: I have a set of data frames that I want to do the same calculations on each. I've found out that I can put them in a list and loop through the list to do the calculation, but not put the results back into each data.frame.. For example three data frames cats, dogs, birds where >cats name eats_kg 1 bob 3 2 garfield 4 3 chuck 6 and dogs and birds are similar but not
2012 Nov 12
3
select different variables from a list of data frames
Hi: How do I select different variables from a list of data frames. I have a list of 13 that looks like below. Each data frame has more variables than I need. How do I go through the list and select the variables that I need. In the example below, I need to get the variables "a", and "q10" and "q14" to be returned to two separate data frames. Thank you. Yours, Simon
2009 Oct 25
3
NULL elements in lists ... a nightmare
I can define a list containing NULL elements: > myList <- list("aaa",NULL,TRUE) > names(myList) <- c("first","second","third") > myList $first [1] "aaa" $second NULL $third [1] TRUE > length(myList) [1] 3 However, if I assign NULL to any of the list element then such element is deleted from the list: > myList$second <-
2008 Mar 24
1
How to assign multiple return values
Hi, I am moving from MATLAB, where one can easily assign a number of output values from a function like this: [x,y] = myfun(a,b) Then variables x and y can be directly used in the caller workspace. I understand that R functions return a single argument, which could be a list. This in a way makes it possible to return multiple values with a single function call, but accessing the list variables
2007 Oct 20
1
Getting at what a named object represents in a function...
Hi, I'm pretty new to R. I have an object (say a list) and I I have a function that I call on various columns in that list (excuse terminology if it's wrong/ambiguous). Imagine its like this (actual values are unimportant) and called mylist: >mylist A B 1 5 2 5 3 6 4 8 5 0 I have a function: foo = function(param){ #modify list A or B values depending on
2004 May 10
2
Lists and outer() like functionality?
Hi, I'm have a list of integer vectors and I want to perform an outer() like operation on the list. As an example, take the following list: mylist <- list(1:5,3:9,8:12) A simple example of the kind of thing I want to do is to find the sum of the shared numbers between each vector to give a result like: result <- array(c(15,12,0,12,42,17,0,17,50), dim=c(3,3)) Two for() loops is the
2011 Apr 05
1
Help in splitting a list
Dear R users, Let's say I have a list with components being 'm' matrices (as exemplified in the "mylist" object below). Now, I'd like to subset this list based on an index vector, which will partition each matrix 'm' in 2 sub-matrices. My questions are: 1. Is there an elegant way to have the results shown in mylist2 for an arbitrary number of matrices in mylist?
2017 Jun 15
4
is.null(mylist[1]) and is.null(mylist$a) returns different values
Hi I have a list : mylist <- list( a = NULL, b = 1, c = 2 ) > mylist[1] $a NULL > is.null(mylist[1]) [1] FALSE > is.null(mylist$a) [1] TRUE why? I need to use mylist[1]
2005 Jan 30
3
trellis graphics in loops
I have this awkward problem with trellis (lattice). I am trying to generate some plots through loops but the .eps file is empty. When I generate them in a list and print them outside the loop all is fine. this is an example below:( nothing shows up in foo.eps, but all show up in foo1.eps) R vesion 2.0.1, lattice version 0.10-16, on a debian 2.6.8-1 kernel. X <- data.frame(x=rnorm(10000),
2001 Oct 18
2
Parsing for list components
How do I parse an identifier of a list component, e.g. mylist$mycomponent or mylist[[1]] ? Parse does not do the job, e.g. parse(text="mylist$mycomponent") returns an expression with just one term, instead of "mylist", "$", "mycomponent". What I need is a way to extract the list name (e.g. "mylist"), given an identifier of a component.
2010 Sep 04
4
Please explain "do.call" in this context, or critique to "stack this list faster"
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
2011 Apr 03
1
Help in splitting ists into sub-lists
Dear List, Let's say I have a list whose components are 2 matrices (as exemplified in the "mylist" object below). I'd like to create a list with components being 4 matrices based on an logical index vector. is there a way to simplify what I'm doing to obtain the results in "mylist2"? I'd like something that would work on an arbitrary number of elements in
1999 May 09
1
subscripting in list() (PR#187)
Sorry My previous report is not detailed. In R, you will get this: > mylist <- list() > mylist[[1]] Error in mylist[[1]] : subscript out of bounds > mylist[[1]] <- c(1) Error: (list) object cannot be coerced to vector type 14 > mylist[[1]] <- c(1,2) > mylist[[1]] <- c(1) > mylist [[1]] [1] 1 I was trying to assigning c(1) to (mylist[[1]] <- c(1)) -- it seems
2010 Mar 18
1
Substitute NAs in a data frame
Excuse me for what I'm sure is a stupid beginner's question, but I've given up trying to find the answer to this question from the help, RSiteSearch, or any of the usual places. I have a list that looks like this: >myList $first [1] "--" "18" "8" "32" $second [1] "--" "--" "40" "54" I want a