Displaying 20 results from an estimated 8000 matches similar to: "creating a file of p.values"
2008 Oct 22
1
Saving kruskal wallis p-values
Hi everyone,
I am working on analyzing spectra which requires hundreds of kruskal wallis
tests to be performed. Once significant results are found post tests are
performed ect. My questions are: how do I perform all these kw tests and
save just the pvalues in a table? Is there anyway to have R automatically
perform post tests if a result of p<0.05 is found? Currently when I run the
test
2012 Jan 10
4
2 sample wilcox.test != kruskal.test
Hello,
I think I am right in saying that a 2 sample wilcox.test is equal to a 2
sample kruskal.test and
a 2 sample t.test is equal to a 2 sample anova. This is also stated in the
?kruskal.test man page:
The Wilcoxon rank sum test (wilcox.test) as the special case for two
samples; lm together with anova for performing one-way location analysis
under normality assumptions; with Student's t
2010 Feb 24
1
extracting results from wilcox_test (package::coin)
Recently, I ran a series of Kruskal-Wallace tests [kruskal.test()] using by()
to group by site Output is a list:
>Herb.KW
Herb.df$ID: 10-1
Kruskal-Wallis rank sum test
data: Indicator_Rating by Year
Kruskal-Wallis chi-squared = 15.24, df = 7, p-value = 0.03302
-----------------------------------------------------------------------------------------------------
Herb.df$ID: 18-1
2008 Aug 21
1
Kruskal.test() on lists
Hi,
I am trying to do a kruskal wallis test on two lists, fVisited and cSN:
fVisited[[1]]
[1] 0.17097623 0.30376141 0.17577266 0.14951855 0.03959753 0.08096217 0.05744888 0.02196257....
....
cSN[[1]]
[1] 0.08557303 0.36477791 0.19601252 0.12981040 0.05351320 0.10385542 0.03539577 0.03106175....
So if I just want to do a test on just one of the entries this is simple enough:
2005 Jan 17
5
find source code
I am using R 2.0.2 on a WinXP
I am trying to get the code of the Kruskal-Wallis test but
> kruskal.test
function (x, ...)
UseMethod("kruskal.test")
<environment: namespace:stats>
> ls(3)
[1] "acf" "acf2AR" "add.scope"
..............
[181] "kruskal.test" "ks.test"
2010 Feb 18
2
Extracting values from a list
I have run a kruskal.test() using the by() function, which returns a list of
results like the following (subset of results):
Herb.df$ID: 4-2
Kruskal-Wallis chi-squared = 18.93, df = 7, p-value = 0.00841
--------------------------------------------------------------------
Herb.df$ID: 44-1
Kruskal-Wallis chi-squared = 4.43, df = 6, p-value = 0.6187
So then, how do extract a vector
2013 Apr 15
1
Kruskal-Wallis
Hi,
I have got two groups of samples; and for every row, I wish to calculate
Kruskal-Wallis' p-value.
In the example below, and the stars (****) show where I am struggling to
design and put things together. Any help would be appreciated.
myFile <- data.frame(Sample_1a = 1:10, Sample_1b = 2:11, Sample_1c = 3:12,
Sample_2a=4:13, Sample_2b=7:16, row.names=LETTERS[1:10])
groups <- rep
2013 Jul 09
1
Kruskal.test
Hi,
?kruskal.test()
?a<- c(2,4,5,2,7)
?b<- c(2,2,6)
?c<- c(3,7,9,3)
?kruskal.test(list(a,b,c))
#
?#? Kruskal-Wallis rank sum test
#
#data:? list(a, b, c)
#Kruskal-Wallis chi-squared = 2.003, df = 2, p-value = 0.3673
A.K.
Hi
I need an expression in R to apply a kruskal.test to this data (for example).
a ? a ? a ? a ? ?a ? ?b ? b ? ?b ? ?c ? ?c ? c ? ?c
2 ?4 ? ?5 ? 2 ? ?7 ? ?2 ? 2 ?
2012 Jun 11
1
Kruskal Wallis Post hoc
Hi, I have searched and found a response to a question similar to mine but
when I tried the code, R says it's not an actual function so I thought I'd
ask here.
http://r.789695.n4.nabble.com/file/n4633035/Cookies.csv Cookies.csv
I have attached the data I am using. I am trying to look at two things: how
moisture content changes over time, and how it changes along the length of a
log
2008 Oct 16
2
Saving results of Kruskal Walis test
Hello,
I am running Kruskal-Walis test in R. When I try to save results using
write.table it gives me the following error :
Error in as.data.frame.default(x[[i]], optional = TRUE, stringsAsFactors =
stringsAsFactors) :
cannot coerce class "htest" into a data.frame
The overall code is as follows :
>data_file = read.table("~/DATA.dir/data_file.txt", header=T)
2009 Oct 14
3
post-hoc test with kruskal.test()
Dear R users,
I would like to know if there is a way in R to execute a post-hoc test
(factor levels comparison, like Tukey for ANOVA) of a non-parametric
analysis of variance with kruskal.test() function. I am comparing three
different groups. The preliminary analysis using the kruskal-wallis-test
show significance, but I still don''t know the relationship and the
significance level
2009 Sep 07
1
Equivalence of Mann-Whitney test and Kruskal-Wallis test with k=2
Hi all,
The Kruskal-Wallis test is a generalization of the two-sample Mann-Whitney
test to *k* samples. That being the case, the Kruskal-Wallis test with *k*=2
should give an identical p-value to the Mann-Whitney test, should it not?
x1<-c(1:5)
x2<-c(6,8,9,11)
a<-wilcox.test(x1,x2,paired=FALSE)
b<-kruskal.test(list(x1,x2),paired=FALSE)
a$p.value
[1] 0.01587302
b$p.value
[1]
2010 Oct 27
1
(no subject)
I am interested in using "multcompLetters" after running "kruskalmc" but
I'm a newbie and I'm not having luck figuring it out. I can run "kruskalmc" just fine,
but after studying the documentation for "multcompletters" for a long time,
I cannot figure out how to make it work. Any ideas? R input is below
>
>> #here is my data set
>>
2014 Jan 20
3
Creación de un bucle con test Kruskal Wallis
Hola.
Llevo poco tiempo con R y estoy atascado en un problemilla, a ver si
podéis ayudarme. Estoy trabajando con una base de datos sobre personalidad
en diferentes especies de aves. Esta base tiene datos de más de 7000
individuos y me gustaría crear un bucle mediante el cual realizar un test
de Kruskal Wallis por cada especie (quiero ver si los comportamientos son
consistentes dentro de cada
2012 Dec 15
3
kruskalmc, significant differences while median values are the same
Dear list!
I work with multiple Kruskal-Wallis test (kruskalmc, package pgirmess), which evaluates differences in medians among groups (5 groups). A result of a test is significant differences among some groups, while median values are the same for 4 groups (using tapply). Why?
p.s.: number of samples in groups vary from 50 to 4900.
Thanks to all, OV
.
2003 Nov 21
2
kruskal wallis for manova?
Hello,
Is there like the kruskal wallis test in relation to ANOVA (no
restrictions on normallity and variance homogenity) something (in R)
for MANOVA?
thanks
--
Dr.Nicolaas Busscher Universit?t GH Kassel
Nordbahnhofstrasse: 1a, D-37213 Witzenhausen
Phone: 0049-(0)5542-98-1715, Fax: 0049-(0)5542-98-1713
2012 Jan 12
2
kruskal wallis post hoc?
Dear all,
I run a kruskal wallis test and found significant results. Then, I conducted all pairwise comparisons and found no significant results. Could anyone please give me a hint as to why this happens or redirect me towards a specific web page where I can find more info? (I used alpha=5% and made no bonferroni or other correction for the pairwise comparisons)
Thank you
Dr. Iasonas
2010 Aug 03
3
Kruskal Walllis test
Hi all
My data table (g) contains a continues data column (plant.height) and other
columns (columns 8 to 57),
each with number of levels of different factors. ANOVA test was done and
the p-values were extracted
as follos:
a <- function(x) anova(lm(plant.height ~ x))$"Pr(>F)"[1]
r<- apply(g[,8:57],2,a)
If I try to do a Kruskal-Wallis test :
kw <- function(x)
2006 Mar 04
1
Npmc for doing post-hoc after Kruskal
I followed the threads that enquired about doing post-hoc tests after doing
Kruskal testing. It took me to npmc. But npmc is giving an output I do not
understand.
I noticed a thread entitled "npmc function: 'x' must be atomic" but there
never appeared to be a resolution.
> npmc(npmcinput)
Error in sort(unique.default(x), na.last = TRUE) :
'x' must be atomic
2011 Nov 21
2
count ties after rank?
Hello!
I need to use Kruskal-Wallis test and post-hoc test (Dunn's test) for my data. But when I searched around, I only found this function: kruskal.test. But nothing for Dunn's test.
So I started to write one myself. But I do not know how to count ties in the data frame. I can use for loops but it seems long and unnecessary since the rank function actually knows the ties. So