Displaying 20 results from an estimated 10000 matches similar to: "Using combn"
2010 Mar 26
2
More efficient alternative to combn()?
Hi,
i am working on a problem where i need to compute the products of all
possible combinations of size m of the elements of a vector. I know that
this can be achieved using the function combn(), e.g.:
> vector <- 1:6
> combn(x = vector, m = 3, FUN = function(y) prod(y))
In my case the vector has 2000 elements and i need to compute the values
specified above for m = 32. Using combn() i
2012 Nov 16
1
pairing data using combn with criteria
Dear All,
I have a dataframe made up of individual beetles consisting of individual
number, family number, mother's family number, father's family number, and
sex of the beetle. I would like to pair up the individuals for breeding. I
would, however, like to avoid breeding beetles of the same sex (obviously),
the same family, and with the same mother's family or father's family,
2010 Apr 07
1
combn with factors
Dear list,
I have come across this issue:
combn(letters[1:5], 3)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] "a" "a" "a" "a" "a" "a" "b" "b" "b" "c"
[2,] "b" "b" "b" "c" "c" "d" "c"
2011 Oct 16
1
multicore combn
This is a 'rather than re-invent the wheel' post. Has anyone out there
re-written combn so that it can be parallelized - with multicore, snow, or
otherwise? I have a job that requires large numbers of combinations, and
rather than get all of the index values, then crank it through mclapply, I
was wondering if there was a way to just do this natively within a function.
Just curious.
2006 May 09
1
combn(n, k, ...) and all its re-inventions
It seems people are reinventing the wheel here:
The goal is to generate all combinations of 1:n of size k.
This (typically) results in a matrix of size k * choose(n,k)
i.e. needs O(n ^ k) space, hence is only applicable to
relatively small k.
Then alternatives have been devised to generate the combinations
"one by one", and I think I remember there has been a
quiz/challenge about 20
2009 Sep 21
2
Combine vectors in order to form matrixes with combn
Hello!
I've a problem with the combn function and a set of vector. I
would like to make a simple combination where, instead of scalars, i
would like to combine vector, in order to form matrixes.
In other
words, i have nineteen 6-items vectors (for example coef1-coef19), that
i would like to combine in n!/k!(n-k)! 6x6 matrixes.
I tried with a
code like this
mma <-
2009 Feb 12
3
getting all pairwise combinations of elements in a character string
I'm able to do this as follows, but am wondering if anyone knows a
simpler way which still avoids explicit loops?
> (mystring <- letters[1:5])
[1] "a" "b" "c" "d" "e"
> unlist(sapply(mystring[-length(mystring)],
+ function(x)
paste(x,mystring[(grep(x,mystring)+1):length(mystring)],sep="")))
a1 a2 a3
2008 Feb 08
2
Applying lm to data with combn
http://www.nabble.com/file/p15359204/test.data.csv
http://www.nabble.com/file/p15359204/test.data.csv test.data.csv
Hi,
I have used apply to have certian combinations, but when I try to use these
combinations I get the error
[Error in eval(expr, envir, enclos) : object "X.GDAXI" not found]. being a
novice I donot understand that after applying combination to the data I cant
access
2013 Jan 24
2
Please help R error message "masked from 'package:utils':combn"
Hi
The message occurred from R, when I was selected of "optimization > block
diagonal Fhiser matrix" and used the attached file on PFIM.
Could you please advise me about the following message?
*****************************
Loading required pakage: combinat
Attaching package:'combinat'
The following object(s) are masked from 'package:utils':combn
2007 Sep 26
2
date
Hello,
I have got the following problem:
> setwd("C:/temp")
> library(xlsReadWrite)
> MyData <- read.xls(file="Mappe1.xls", colNames = TRUE,dateTimeAs = "isodatetime")
> attach(MyData)
> MyData
name value times
1 A1 2 2006-05-12
2 A2 3 2006-05-16
3 A3 1 2006-05-12
4 A4 4 2006-05-12
5 A5 2
2009 Mar 02
2
ave and grouping
Dear list,
# I have a DF like this:
sleep$b <- c(rep(8,10), rep(9,10))
sleep$me <- with(sleep, ave(extra, group, FUN = mean))
sleep
# I would like to create a new variable
# holding the b-th value of group 1 and 2.
# This is not what I want, it takes always the '8' from group '1'
# and not the '9'
sleep$gr <- with(sleep, ave(extra, group, FUN = function(x)
2012 Jul 20
6
Speeding up a loop
General problem: I have 20 projects that can be invested in and I need to
decide which combinations meet a certain set of standards. The total
possible combinations comes out to 2^20. However I know for a fact that the
number of projects must be greater than 5 and less than 13. So far the the
code below is the best I can come up with for iteratively creating a set to
check against my set of
2007 Mar 27
2
Newbie: Combn and scripting
Hello All,
I have just installed my R 2.4 (windows) as a test trying to load a data
frame and run combn() for each line into another file. How do I do this?
data.csv:
a,b,c,d
1,2,3.4
g,3,6,t
etc
x=data.csv, m=3
Thank you
Zam
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2007 Jan 19
2
combn implementation
Hi,
I was checking the source code to the function combn that "generates
all combinations of the elements of 'x' taken 'm' at a time.",
because I wished to modify it. I have a doubt about a statement.
This is the main loop.
._1 <- 1:1
nmmp1 <- n - m + ._1
while (a[1] != nmmp1) {
if (e < n - h) {
h <- ._1
e <-
2010 Apr 13
2
sensitivity analysis, input factors
Hi,
I'm trying to conduct sensitivity analysis in R using the 'sensitivity' package. Although the description of functions seem straightforward, I can?t succeed. The definition of input factors can be the problem.
library(sensitivity)
#A simple model with 4 input factor to test the morris function:
model01=function(a1,a2,a3,a4)
{
Z<-numeric(10)
Z[1]<-runif(1)
2005 Mar 19
2
simple problem, but not for me
Hello, I'm new in R and I want to do one thing that is very easy in excel, however, I cant do it in R.
Suppose we have the data frame:
data<- data.frame(A=c("a1","a2","a3","a4","a5"))
I need to obtain another column in the same data frame (lets say B=c(b1,b2,b3,b4,b5) in the following way:
b1=a1/(a1+a2+a3+a4+a5)
2009 Apr 26
2
Help to select the raw in a data.frame with the max value
Dear User,
thank for the attention. I have a data.frame with 5 columns (ex:ID,
a1,a2,a3,a4) and 1000 rows. I wish to find the absolute max value for all
data.frame and save a new data.frame with the row where is that value. Ex:
ID: 1,2,3,4,5,6,7,8,9,10
a1:1,2,3,4,5,6,7,8,9,10
a2:11,12,13,14,15,16,17,18,19,20
a3:21,22,23,24,25,26,27,28,29,30
a4:31,32,33,34,35,36,37,38,39,40
The
2009 Oct 29
3
Removing & generating data by category
Dear R users,
Basically, from the following arbitrary data set:
a <-
data.frame(id=c(c("A1","A2","A3","A4","A5"),c("A3","A2","A3","A4","A5")),loc=c("B1","B2","B3","B4","B5"),clm=c(rep(("General"),6),rep("Life",4)))
> a
2008 Feb 10
2
reshape
Dear colleagues,
I'd like to reshape a datafame in a long format to a wide format, but
I do not quite get what I want. Here is an example of the data I've
have (dat):
sp <- c("a", "a", "a", "a", "b", "b", "b", "c", "d", "d", "d", "d")
tr <- c("A",
2013 Feb 07
1
Merging data in arrays
Dear All,
Here is a hypothetical sample (sorry for the clumsy code):
A1 <- matrix(1:5, nrow=5, ncol=1)
A2 <- matrix(6:10, nrow=5, ncol=1)
A3 <- matrix(11:15, nrow=5, ncol=1)
A4 <- matrix(16:20, nrow=5, ncol=1)
A5 <- matrix(21:25, nrow=5, ncol=1)
A6 <- matrix(26:30, nrow=5, ncol=1)
B1 <- matrix(c(A1, A2, A3), nrow=5, ncol=3)
B2 <- matrix(c(A2, A3, A4), nrow=5, ncol=3)
B3