Displaying 20 results from an estimated 10000 matches similar to: "Adding elements in an array where I have missing data."
2013 Dec 06
2
Using assign with mapply
I have a data frame whose first colum contains the names of the variables
and whose second colum contains the values to assign to them:
: kkk <- data.frame(vars=c("var1", "var2", "var3"),
vals=c(10, 20, 30), stringsAsFactors=F)
If I do
: assign(kkk$vars[1], kkk$vals[1])
it works
: var1
[1] 10
However, if I try with mapply
2003 Oct 14
3
mapply() gives seg fault
Hello everybody.
I've been experimenting with mapply(). Does anyone else have problems with:
R> mapply(rep,times=1:4, MoreArgs=42)
(I get a seg fault).
robin
R> R.version
_
platform powerpc-apple-darwin6.6
arch powerpc
os darwin6.6
system powerpc, darwin6.6
status beta
major 1
minor 8.0
year 2003
month 10
day 02
language R
>
2010 Nov 15
3
indexing lists
Hi List,
I'm trying to work out how to use which(), or another function, to find the
top-level index of a list item based on a condition. An example will clarify
my question.
a <- list(c(1,2),c(3,4))
a
[[1]]
[1] 1 2
[[2]]
[1] 3 4
I want to find the top level index of c(1,2), which should return 1 since;
a[[1]]
[1] 1 2
I can't seem to work out the syntax. I've tried;
which(a
2005 Nov 20
1
mapply() gives seg fault (PR#8332)
--KsGdsel6WgEHnImy
Content-Type: text/plain; charset=iso-8859-1; format=flowed
Content-Disposition: inline
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Hi, people. Wandering in R archives, and seeing the message attached
below, I noticed that:
mapply(rep,times=1:4, MoreArgs=42)
still segfaults on R 2.2.0, and thought I should be a good citizen and
report it, even if I do not have an actual problem
2006 Aug 31
2
Wish: keep names in mapply() result
Hello!
I have noticed that mapply() drops names in R 2.3.1 as well as in
r-devel. Here is a simple example:
l <- list(a=1, b=2)
k <- list(1)
mapply(FUN="+", l, k)
[1] 2 3
mapply(FUN="+", l, k, SIMPLIFY=FALSE)
[[1]]
[1] 2
[[2]]
[1] 3
Help page does not indicate that this should happen. Argument USE.NAMES
does not have any effect here as it used only in a bit special
2011 Sep 02
3
merge some columns
Dear all,
I would like to know how to merge columns like:
Input file:
V1 V2 V3 V4 V5 V6
1 G A G G G G
2 A A G A A G
Desired output file:
V1 V2 V3
1 G/A G/G G/G
2 A/A G/A A/G
So for every 2 consecutive columns merge their content into one.
Thanks in advance.
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2008 Mar 07
3
merging environments
Despite the spirited arguments of various R-core folks
who feel that mle() doesn't need a "data" argument, and
that users would be better off learning to deal with function
closures, I am *still* trying to make such things work
in a reasonably smooth fashion ...
Is there a standard idiom for "merging" environments?
i.e., suppose a function has an environment that I want
2009 Mar 07
2
Recode factor into binary factor-level vars
How to I "recode" a factor into a binary data frame according to the
factor levels:
### example:start
set.seed(20)
l <- sample(rep.int(c("locA", "locB", "locC", "locD"), 100), 10,
replace=T)
# [1] "locD" "locD" "locD" "locD" "locB" "locA" "locA" "locA"
2012 Dec 11
1
Rprof causing R to crash
I'm trying to use Rprof() to identify bottlenecks and speed up a particullary
slow section of code which reads in a portion of a tif file and compares
each of the values to values of predictors used for model fitting. I've
written up an example that anyone can run. Generally temp would be a
section of a tif read into a data.frame and used later for other processing.
The first portion
2011 Feb 02
2
Help me apply mapply
Hello all I would like to ask your help use mapply.
I have a function called findCell that takes two arguments(x,sr)
where x is a vector of size two (e.g x<-c(2,3) and sr is a matrix.
I would like to call many times the findCell function (thus I need mapply) for different x inputs but always for the same sr.
as x is a vector of size two (two cells) I want to pass inside inside the following
2013 Mar 12
2
Bugs due to naive copying of list elements
Several bugs are present in R-2.15.3 and R-alpha due to
naive copying of list elements.
The bug below is due to naive copying in subset.c (with
similar bugs for matrices and arrays):
a<-list(c(1,2),c(3,4),c(5,6))
b<-a[2:3]
a[[2]][2]<-9
print(b[[1]][2])
Naive copying in mapply.c leads to the following bug:
X<-1+1
f<-function(a,b) X
A<-mapply(f,c(1,2,3),c(4,5,6),SIMPLIFY=FALSE)
2006 Mar 14
1
R CMD check: problems possibly from mapply?
Dear expeRts,
I am trying to wrap up a package "utilities" (for my internal use). After
adding a function datNAtreat that uses mapply, R CMD check gives WARNINGs
for "S3 generic/method consistency", "checking replacement functions"
and?"checking foreign function calls", all of which are accompanied by the
following error message:
Error in .try_quietly
2005 Oct 07
6
Applying a function to each element of an array
Hi,
I have a 7000x7000 matrix, and each element is an integer. For each element, I want to apply the function :
wt <- 0
for(q in 1:count){
wt <- wt + 0.5^(q-1)
}
I get the value of 'count' from the elements in the matrix , and want to store the corresponding 'wt' value for that element.
I suppose I could loop through the matrix, and apply the function to each
2006 Jun 29
3
advice on arguments
I have a general style question about R coding.
Suppose I'm writing a function (foo1) that calls other functions
(foo2, foo3, ...) which have complicated argument
lists (e.g. optim(), plot()), _and_
I may be calling several different functions in the body of
foo1. Since foo2 and foo3 have different sets of arguments, I
can't just use "..." ; I did write some code a while ago
2011 Feb 23
2
list multiplied by a factor / mapply
Dear list,
this works fine:
x <- split(iris, iris$Species)
x1 <- lapply(x, function(L) transform(L, g = L[,1:4] * 3))
but I would like to multiply each Species with another factor:
setosa by 2, versicolor by 3 and virginica by 4. I've tried mapply but
without success.
Any thoughts? Thanks for any idea!
Patrick
2011 Sep 29
1
Looking for internal of a function
Dear all, when I look at the internal of mapply() function, I see a line of
code:
answer <- .Call("do_mapply", FUN, dots, MoreArgs, environment(),
PACKAGE = "base")
Can somebody please tell me how to find the source code of 'do_mapply'
Thanks,
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2010 Dec 02
2
Hmisc label function applied to data frame
Hello,
I'm attempting to create a data frame with correlations between every pair
of variables in a data frame, so that I can then sort by the value of the
correlation coefficient and see which pairs of variables are most strongly
correlated.
The sm2vec function in the corpcor library works very nicely as shown here:
library(Hmisc)
library(corpcor)
# Create example data
x1 = runif(50)
x2 =
2009 Oct 14
1
using mapply to avoid loops
Hello, I would like to use mapply to avoid using a loop but for some reason, I can't seem to get it to work. I've included copies of my code below. The first set of code uses a loop (and it works fine), and the second set of code attempts to use mapply but I get a "subscript out of bounds" error. Any guidance would be greatly appreciated. Xj, Yj, and Wj are also lists, and s2,
2006 Jul 20
2
Timing benefits of mapply() vs. for loop was: Wrap a loop inside a function
List:
Thank you for the replies to my post yesterday. Gabor and Phil also gave
useful replies on how to improve the function by relying on mapply
rather than the explicit for loop. In general, I try and use the family
of apply functions rather than the looping constructs such as for, while
etc as a matter of practice.
However, it seems the mapply function in this case is slower (in terms
of CPU
2010 Nov 23
3
how to update my own function
Hello all,
I wrote a function with many arguments. Then I need to call it many times
with changes on some arguments only. Is there any way to write a function or
have a method to "update" it, like the relationship between lm() and
update()?
Many thanks,
Edwin Sun
------------
This is the sample code.
> test <- function(y, z) {
+ x <- y +1
+ w <- z * 2
+ result