Displaying 20 results from an estimated 10000 matches similar to: "permutation distribution for Friedman test"
2011 Oct 14
2
non-parametric permutation and signed paired-difference distributions
Hi all
Consider the classic data below from Darwin on the heights of 15 pairs
of zea mays (corn) plants
either cross-fertilized or self-fertilized, where the goal is to see if
it makes a difference.
> head(ZeaMays)
pair pot cross self diff
1 1 1 23.500 17.375 6.125
2 2 1 12.000 20.375 -8.375
3 3 1 21.000 20.000 1.000
4 4 2 22.000 20.000 2.000
5 5 2 19.125
2008 Apr 02
0
Exact Permutation test
R users,
Is it possible to do 'exact' permutation tests in R? If I run a perm.test or
permutation.test.discrete on a data set that has, for example, 720 possible
permutations, will that test permute ALL of those possible permutations, or
will it just permute 720 random permutations (thus allowing some
possibilities to repeat and some not to be permuted at all)?
I'm a little confused
2009 May 20
1
Comparing spatial distributions - permutation test implementation
Hello everyone,
I am looking at the joint spatial distribution of 2 kinds of organisms
(estimated on a grid of points) and want to test for significant
association or dissociation.
My first question is: do you know a nice technique to do that,
considering that I have a limited number of points (36) but that they
are repeated (4 times)? I did GLMs to test for correlations between
the
2004 Apr 17
0
nlme - sum of squares - permutation test
Hi,
1/ I wonder why a anova.lme on a single lme object does not print the sum of squares (as expected from the help: "a data frame with the sums of squares, numerator degrees of freedom, denominator
degrees of freedom, F-values, and P-values").
Example:
> fm2 <- lme(distance ~ age + Sex, data = Orthodont, random = ~ 1)
> anova(fm2)
numDF denDF F-value p-value
2011 Jan 24
2
Masking commands - Permutation in gregmisc and e1071
I am using the function permutations from the package *gregmisc*. However, I
am also making use of the package *e1071*, which also contains a function
called permutations. I want to use the function permutations from the *
gregmisc* package, however, the other package is masking this function. This
happens both when I load the *e1071* package before *gregmisc* and when I
load *e1071* after I load
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
2002 Nov 26
1
permutation
The gregmisc package contains a function 'perumutations' which generates all
permutations of n choose r. It also contains 'combinations' which generates
all combinations, and which appears to match your example:
> library(gregmisc)
Loading required package: MASS
Attaching package `gregmisc':
The following object(s) are masked from package:base :
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
2010 Aug 01
1
Permutation of a sequence to without changing local distribution
Hello All,
Suppose that I have a sequence of letters (e.g., A..Z). I want to
permute the sequence to generate random sequences, such that the local
density of any letter with a window (say of length L) doesn't change
much before and after permutation.
One way that I can thing of is to require that the position of any
letter in the original sequence and the position of the same letter in
the
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
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)
>
>>
2008 Feb 21
1
Permutation Test
Dear R users,
i am fairly new to R and am having trouble creating code to solve a problem.
I've searched the list, combed Crawley's 'R book' and several others, but
can't quite find what i want.
I want to generate permutations of various 'blocks' of 14 numbers. Each
number within a block is a character state for a particular biological
taxon. In the example below, for
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"
2005 Nov 30
1
Permutation tests for correlations
Apropos the question about permutation tests in multiple regression:
We do have perm.test in package ExactRankTests, but it does one- and
two-sample tests, as in t.test, wilcox.test, etc. There doesn't seem
to be an exact version of the permutation test for correlations, i.e.,
the one that could be estimated using
replicate(10000, cor(x,sample(y))) # or other values of 10000
or, of course,
2004 Jul 16
0
Permutations (summary)
Dear R users,
This is a second summary of the permutation problem I previously posted.
This summary restates the problem as well as the solution.
First of all thanks to everyone including Erich, Robin, Gabor, Christian,
Ingmar and others for your suggestions.
With the help of an off-list discussion with Gabor I?m going to summarize.
THE PROBLEM
We have 12 elements in blocks of 3 :
1 2
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
2006 Oct 23
1
Lmer, heteroscedasticity and permutation, need help please
Hi everybody,
I'm trying to analyse a set of data with a non-normal response, 2 fixed
effects and 1 nested random effect with strong heteroscedasticity in the
model.
I planned to use the function lmer : lmer(resp~var1*var2 + (1|rand)) and
then use permutations based on the t-statistic given by lmer to get
p-values.
1/ Is it a correct way to obtain p-values for my variables ? (see below)
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
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
2009 Nov 12
2
A combinatorial optimization problem: finding the best permutation of a complex vector
Hi,
I have a complex-valued vector X in C^n. Given another complex-valued vector Y in C^n, I want to find a permutation of Y, say, Y*, that minimizes ||X - Y*||, the distance between X and Y*.
Note that this problem can be trivially solved for "Real" vectors, since real numbers possess the ordering property. Complex numbers, however, do not possess this property. Hence the