similar to: permutation/randomization

Displaying 20 results from an estimated 4000 matches similar to: "permutation/randomization"

2008 Apr 19
1
resampling from distributions
Hello All, Once again thanks for all of the help to date. I am climbing my R learning curve. I've got a few more questions that I hope I can get some guidance on though. I am not sure whether the etiquette is to break up multiple questions or not but I'll keep them together here for now as it may help put the questions in context despite the fact that the post may get a little long.
2010 Jan 28
2
Constrained vector permutation
Hello, I'm trying to permute a vector of positive integers > 0 with the constraint that each element must be <= twice the element before it (i.e. for some vector x, x[i] <= 2*x[i-1]), assuming the "0th" element is 1. Hence the first element of the vector must always be 1 or 2 (by assuming the "0th" element is 1). Similarly, the 2nd must always be below/= 4, the
2011 May 23
1
help on permutation/randomization test
Hi, I have two groups of data of different size: group A: x1, x2, ...., x_n; group B: y1, y2, ...., y_m; (m is not equal to n) The two groups are independent but observations within each group are not independent, i.e., x1, x2, ..., x_n are not independent; but x's are independent from y's I wonder if randomization test is still applicable to this case. Does R have any function
2006 May 03
1
Permutation test of marked point pattern
Dear R users, I am trying to perform a hypothesis test on a marked point pattern. I would like to calculate the mean of the absolute value of the difference of marks between nearest neigbours, randomize the marks among points, then calculate this mean again. Ideally, I would test whether random mean values smaller than the observed mean value occur less than 5% of the time. I suppose 1000
2018 May 23
3
find the permutation function of a sorting
Thanks, David. I got the answer from the web. Is there any easy way to permute a set (e.g., a set of characters) by the permutation it returns? Thanks, > x <- c(10,7,4,3,8,2) > sort(x, index.return=TRUE) $x [1] 2 3 4 7 8 10 $ix [1] 6 4 3 2 5 1 2018-05-23 10:49 GMT+08:00 David Winsemius <dwinsemius at comcast.net>: > > > > On May 22, 2018, at 10:06 PM, John
2007 Oct 02
1
permutations of a binary matrix with fixed margins
J?r?me, As a first attempt, how about the function below. It works (or not) by randomly sorting the rows and columns, then searching the table for "squares" with the corners = matrix(c(1,0,0,1),ncol=2) and subtracting them from 1 to give matrix(c(0,1,1,0),ncol=2) (and vice versa). Randomized matrices can be produced as a chain where each permutation is seeded with the previous one.
2018 May 23
0
find the permutation function of a sorting
> On May 22, 2018, at 10:57 PM, John <miaojpm at gmail.com> wrote: > > Thanks, David. > I got the answer from the web. > Is there any easy way to permute a set (e.g., a set of characters) by the permutation it returns? Thanks, > > > > x <- c(10,7,4,3,8,2) > > sort(x, index.return=TRUE) > $x > [1] 2 3 4 7 8 10 > > $ix > [1] 6 4 3 2
2018 May 23
2
find the permutation function of a sorting
Hi, Is there any way to find the permutation function of the sorting and to apply the function (or its inverse) elsewhere? For example, the following permutation function from the sorting in the matrix form is c(1,2,3), c(2,1,3) > sort(c("bc","ac","dd")) [1] "ac" "bc" "dd" I try to find it in the permutations/permute
2005 Nov 29
2
permutation test for linear models with continuous covariates
Hi I was wondering if there is a permutation test available in R for linear models with continuous dependent covariates. I want to do a test like the one shown here. bmi<-rnorm(100,25) x<-c(rep(0,75),rep(1,25)) y<-rnorm(100)+bmi^(1/2)+rnorm(100,2)*x+bmi*x H0<-lm(y~1+x+bmi) H1<-lm(y~1+x+bmi+x*bmi) anova(H0,H1) summary(lm(y~1+x+bmi)) But I want to use permutation testing to
2018 May 23
3
find the permutation function of a sorting
> sort(c("bc","ac","dd"), index.return=TRUE) $x [1] "ac" "bc" "dd" $ix [1] 2 1 3 We have the permutation, namely 1-->2, 2-->1, 3-->3. How can I apply the permutation function to a new set c("D","E", "F")? so that the result is c("E","D", "F"). 2018-05-23 11:06
2009 Mar 11
1
OT: Likelihood ratio for the randomization/permutation test?
Hi guRus, My discipline (experimental psychology) is gradually moving away from Null Hypothesis Testing and towards measures of evidence. One measure of evidence that has been popular of late is the likelihood ratio. Glover & Dixon (2005) demonstrate the calculation of the likelihood ratio from ANOVA tables, but I'm also interested in non-parametric statistics and wonder if anyone has any
2018 May 23
0
find the permutation function of a sorting
> On May 22, 2018, at 10:06 PM, John <miaojpm at gmail.com> wrote: > > Hi, > > Is there any way to find the permutation function of the sorting and to > apply the function (or its inverse) elsewhere? > > For example, the following permutation function from the sorting in the > matrix form is > c(1,2,3), c(2,1,3) > >>
2006 Jul 20
3
Permutation Distribution
Hallo Is there an elegant way to do the following: Dataset consists of 2 variables: var1: some measurements, and var2: a grouping variable with two values, 1 and 2. There are (say) 10 measurements from group 1 and 15 measurements from group 2. The idea is to study the permutation distribution of mean(group 1) * mean(group2). One way would be to permute 1s and 2s and select the corresponding
2011 Dec 20
1
column permutation of sparse matrix
Hi, I'm very new to working with sparse matrices and would like to know how I can column permute a sparse matrix. Here is a small example: > M1 <- > spMatrix(nrow=5,ncol=6,i=sample(5,15,replace=TRUE),j=sample(6,15,replace=TRUE),x=round_any(rnorm(15,2),0.001)) > M1 5 x 6 sparse Matrix of class "dgTMatrix" [1,] 2.983 . 1.656 5.003 . . [2,] .
2018 May 23
0
find the permutation function of a sorting
Hello, Like David said, what you are trying to do with sort() can be done with order() in a much easier way. First, your code x <- sort(c("bc","ac","dd"), index.return=TRUE) Now, with function order() i <- order(c("bc", "ac", "dd")) y <- c("D","E", "F")[i] y #[1] "E" "D"
2012 Apr 28
3
Writing a Permutation Function
Hi everyone, I am somewhat new to R and I am trying to write a permutation function such that it inputs a character vector and from an arbitrary length "n" which is the length of the combinations for the character vector. I know there are R packages for permutation but this is for an assignment. So far this is what I have: alphabet =
2007 Nov 16
4
Permutation of a distance matrix
Hi there, I would like to find a more efficient way of permuting the rows and columns of a symmetrical matrix that represents ecological or actual distances between objects in space. The permutation is of the type used in a Mantel test. Specifically, the permutation has to accomplish something like this: Original matrix addresses: a11 a12 a13 a21 a22 a23 a31 a32 a33 Example
2012 Jun 09
2
Help with permutation function from Turner et al. 2010 (Ecology)
Hello, I'm using R code that includes a residual permutation that was written as a supplement to the paper: Turner et al. 2010. A general hypothesis-testing framework for stable isotopes ratios in ecological studies. Ecology 91:2227-2233. The supplemental code is available at: http://www.esapubs.org/archive/ecol/E091/157/suppl-1.htm When I execute the function, no warnings are given
2008 Nov 30
2
Randomization of a two-way ANOVA?
Hello list, I wish to perform a randomization test on the F-statistics of a 2 way ANOVA but have not been able to find out how to do so - is there a package / function that can perform this that I am unaware of? FactorA has 6 levels (0,1,2,3,4,5) whereas FactorB has 3 (1,2,3). A sample: Resp. FactorA FactorB 2 0 2 3 1 2 1 2 2 0 3 2 0 4 2 0 5 2 4 0 1 6 1 1 1 2 1 0 3 1 1 4 1 0 5 1 2 0 2 3 1 2 1
2012 Mar 09
2
(Fisher) Randomization Test for Matched Pairs: Permutation Data Setup Based on Signs
Hi, I am currently attempting to write a small program for a randomization test (based on rank/combination) for matched pairs. If you will please allow me to introduce you to some background information regarding the test prior to my question at hand, or you may skip down to the bold portion for my issue. There are two sample sizes; the data, as I am sure you guessed, is matched into pairs and