Displaying 20 results from an estimated 5000 matches similar to: "Elementary questions about data structures"
2003 Dec 02
2
model of fish over exploitation
Dear all,
I have a serious problem to solve my model. I study over exploitation of
fish in the bay of biscay (france). I know only the level of catch and
the fishing effort (see data below) by year.
My model is composed by the following equations:
* the growth function
Gt(St) = r*St*(1-St/sbar)
with Gt the growth of each period t
r intrinsec growth of the stock
sbar carriyng capacity of the
2010 Feb 26
3
Preserving lists in a function
Dear R users,
A co-worker and I are writing a function to facilitate graph plotting in R. The function makes use of a lot of lists in its defaults.
However, we discovered that R does not necessarily preserve the defaults if we were to input them in the form of list() when initializing the function. For example, if you feed the function codes below into R:
myfunction=function(
list1=list
2004 Oct 25
1
usage and behavior of 'setIs'
Hello,
am I using 'setIs' in the correct way in the subsequent (artifical) example?
Do I have to specify explicit 'setAs' for 'list' and 'vector' or
should this work automatically, since "getClass("List1")" states
an explicit coerce also for these classes.
I'm working with R 2.0.0 Patched (2004-10-06) on windows 2000.
Thanks for your
2011 Jan 08
3
Question on list objects
Hi, I have 2 questions on list object:
1. Suppose I have a matrix like:
dat <- matrix(1:9,3)
Now I want to replicate this entire matrix 3 times and put entire result in a list object. Means, if "res" is the resulting list then I should have:
res[[1]]=dat, res[[2]]=dat, res[[3]]=dat
How can I do that in the easilest manner?
2. Suppose I have 2 list objects:
list1 <- list2
2009 Apr 15
6
Intersection of two sets of intervals
Hi,
Algorithm question: I have two sets of "intervals", where an interval is
an ordered pair [a,b] of two numbers. Is there an efficient way in R to
generate the intersection of two lists of same?
For concreteness: I'm representing a set of intervals with a data.frame:
> list1 = as.data.frame(list(open=c(1,5), close=c(2,10)))
> list1
open close
1 1 2
2 5
2010 Mar 15
1
rbind, data.frame, classes
Hi,
This has bugged me for a bit. First question is how to keep classes with
rbind, and second question is how to properly return vecotrs instead of
lists after turning an rbind of lists into a data.frame
list1=list(a=2, b=as.Date("20090102", format="%Y%m%d"))
list2=list(a=2, b=as.Date("20090102", format="%Y%m%d"))
rbind(list1, list2) #this loses the
2012 Apr 19
1
question about lists
I am new to R, and I have been running into the following situation
when I mistype a variable name in some code:
> list1 <- list( a=1, b=2 )
> list2 <- list( a=1 )
> list2$b <- list1$c
> list2
$a
[1] 1
I would think at the point where I am trying to reference a field
called "c" -- that does not exist -- in list1, there would be an error
flagged.
Instead, list1$c
2011 Feb 06
1
Applying 'cbind/rbind' among different list object
Hi, I am wondering whether we can apply 'cbind/rbind' on many **equivalent**
list objects. For example please consider following:
> list1 <- list2 <- vector("list", length=2); names(list1) <- names(list2)
<- c("a", "b")
> list1[[1]] <- matrix(1:25, 5)
> list1[[2]] <- matrix(2:26, 5)
> list2[[1]] <- 10:14
> list2[[2]] <-
2011 Nov 21
1
Creating a list from all combinations of two lists
R-helpers:
Say I have two lists of arbitrary elements, e.g.:
list1=list(c(1:3),"R is fun!",c(3:6))
list2=list(c(10:5),c(5:3),c(13,5),"I am so confused")
I would like to produce a single new list that is composed of all
combinations of the "top level" of list1 and list2, e.g.:
listcombo=list(list(list1[[1]],list2[[1]]),list(list1[[1]],list2[[2]]
2011 Feb 08
2
Extrcat selected rows from a list
Hi,
I have two lists
1) List1- 30,000 rows and 104 columns
2) List2- a list of 14000 selected rownames from List 1
Now, I want to extract all the 104 columns of List1 matching with the 14000 selected rownames from List2.
Psedocode will be something like this:
match rownames(List2) with rownames(List1)
extract selected matched 104 coloumns from (List1)
strore in-> List3
So the
2012 Jul 05
2
vector entry in matix
hi,
i'm trying to figure out if there's any possibility to write a whole vector
into a matrix or data.frame or something like that. i don't mean
transormation. Here an example:
[,1] [,2]
[1,] "a" "d"
[2,] "b" "e"
[3,] "c" "f"
where e.g. a is a<-c(0,1) vector of length 2, b a vector of length 4,... (i
know that
2005 Sep 23
1
Sortable list with Ajax and delete function - working example
Hi.
I read most of the postings here but unfortunately I didin''t found a complete example which could be used. Of cource the ones who are professionals in javascript could implement the missing peaces from the puzzle.
What I''m required to do is a tree (sortable list) where items can also be deleted and at each modification a function (ajax) is called to save the changes. For
2007 Oct 15
1
The "condition has length > 1" issue for lists
I have the following code:
list1 <- list()
for (i in list.files(pattern="filename1")){
x <- read.table(i)
list1[[i]] <- x
}
list2 <- list()
for (i in list.files(pattern="filename2*")){
x <- read.table(i)
list2[[i]] <- x
}
anslist <- vector('list', length(list1))
for(i in 1:length(list1))
if (list1[[i]] & list2[[i]] >1)
2009 Sep 29
1
Comparing vectors from lists
Hi guys,
I still did not solve my problem properly! I have to compare the values of two lists of 250 numbers as a result of using the ?by function!
List1 of 250
$ 0 : num [1:28] 22 11 31...
$ 1 : num [1:15] 12 14 9 ...
..
..
..
- attr(*, "dim")= int 250
- attr(*, "dimnames")=List of 1
List2 of 250
$ 0 : num [1:24] 20 12 22...
$ 1 : num [1:17] 11 12 19 ...
..
..
2011 May 05
1
lapply, if statement and concatenating to a list
Hi R users
I was wondering on how to use lapply & co when the applied function has a conditional statement and the output is a 'growing' object.
See example below:
list1 <- list('A','B','C')
list2 <- c()
myfun <- function(x,list2)
{
one_elem <- x
cat('one_elem= ', one_elem, '\n')
random <- sample(1:2,1)
show(random)
2010 Jun 13
4
Are any values in one list contained within a second list
Silly question, but, can I test to see if any value of list a is contained in
list b without doing a loop? A loop is easy enough, but wanted to see if
there was a cleaner way. By way of example:
List 1: a, b, c, d, e, f, g
List 2: z, y, x, w, v, u, b
Return true, since both lists contain b
List 1: a, b, c, d, e, f, g
List 2: z, y, x, w, v, u, t
Return false, since the lists have no mutual
2005 Jul 18
2
scriptaculous dragdrop.js empty list problem
Hi,
I''ve just been having a look at the scriptaculous drag-n-drop library, which
looks exceedingly good. I''m running across a show-stopper here, though -
something that''s cropping up in both the online demos and my own test scripts. If
I set up two lists so that I can drag items between them, then if either list
becomes empty, I can''t drag elements back into
2007 May 16
2
substitute "x" for "pattern" in a list, while preservign list "structure". lapply, gsub, list...?
I am experimenting with some of the common r functions.
I had a question re:using "gsub" (or some similar functions) on the contents of a list.
I want to design a function that looks at "everything" contained din a list, and anytime it finds the text string "pattern" replace it with "x". I also wish to preserve the "structure" of the original
2004 Jan 24
1
loop variable passage and lists
I cannot understand why the following expression is accepted (and gives the expected result: to set column 3 and 4 of the first
element of list1 -a data.frame list- as first element of list2):
> list2[[1]]<-list1[[1]][3:4]
...while this one is not (to do the same iteratively from the first to the eleventh element of list1):
> for (i in 1:11){list2[[i]]<-list1[[i]][3:4]}
Error in
2006 Oct 28
1
comparing 2 lists
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