Displaying 20 results from an estimated 4000 matches similar to: "kendall tau a,b,c"
2012 Aug 20
1
Kendall package tau-a, b, and c
Hi all,
I would like to ask a question related to Kendall package. I ran Kendall
(x,y) and
saw the results. But I am not sure which tau values R reported. I have
ties in
my data set, so I want tau-b. Can anybody tell how Kendall package is
calculating tau values? I have looked at the package PDF, but I could
not find
any useful information. As long as I see from the following
link, there
2005 Aug 13
1
R/S-Plus/SAS yield different results for Kendall-tau and Spearman nonparametric regression
Colleagues,
I ran some nonparametric regressions in R (run in RedHat Linux), then
a colleague repeated the analyses in SAS. When we obtained different
results, I tested S-Plus (same Linux box). And, got yet different
results. I replicated the results with a small dataset:
DATA:
37.5
23
37.5
13
25
16
25
12
100
15
12.5
19
50
20
100
13
100
10
100
10
100
16
50
10
87.5
2005 Aug 18
2
kendall tau correlation test for ties: Potential error (PR#8076)
Full_Name: Dirk Koschuetzki
Version: 2.1.1
OS: source code
Submission from: (NULL) (194.94.136.34)
Hello,
>From the source code (R-2.1.1, file: .../R-2.1.1/src/library/stats/R/)
******************************
cor.test.default <-
function(x, y, alternative = c("two.sided", "less", "greater"),
method = c("pearson", "kendall",
2009 Dec 13
2
O(N log N) Kendall Tau
I've noticed that the implementation of Kendall's Tau in R is O(N^2).
The following reference describes how it can be done in O(N log N):
A Computer Method for Calculating Kendall's Tau with Ungrouped Data
William R. Knight
Journal of the American Statistical Association, Vol. 61, No. 314, Part
1 (Jun., 1966), pp. 436-439
http://www.jstor.org/pss/2282833
I'm interested in
2006 Sep 12
1
Kendall's tau-c
Hello,
I can't find a package which calculates Kendall's tau-c. There is the
package Kendall, but it only calcuates Kendall's tau-b.
Here is the example from
ttp://www2.chass.ncsu.edu/garson/pa765/assocordinal.htm.
cityriots <- data.frame(citysize=c(1,1,2,2,3,3),
riotsize=c(1,2,1,2,1,2), weight=c(4,2,2,3,0,4))
cityriots <- data.frame(lapply(cityriots,function(x)
2003 Apr 07
1
kendall's tau-b computation (PR#2742)
Full_Name: Dan Field
Version: 1.6.2
OS: N/A
Submission from: (NULL) (209.115.168.187)
In kendall.c (library is ctest), the limits for the first loop in routine
kendall_tau run from 0 through n-1, and the inner loop runs from 0 through i-1.
This causes the each pair at index i to be compared with itself; my
understanding is that there should only be n*(n-1)/2 pairs under consideration
for
2005 Jun 28
1
faster algorithm for Kendall's tau
Hi,
I need to calculate Kendall's tau for large data
vectors (length > 100'000).
Is somebody aware of a faster algorithm or package
function than "cor(, method="kendall")"?
There are ties in the data to be considered (Kendall's
tau-b).
Any suggestions?
Regards
Ferdinand
2008 Nov 21
1
Bug in Kendall for n<4?
> library(Kendall)
> Kendall(1:3,1:3)
WARNING: Error exit, tauk2. IFAULT = 12 <<<<<<
tau = 1, 2-sided pvalue =1
I believe Kendall tau is well-defined for this case and the reported
value is correct; isn't it a bug to give a warning? (And if, e.g.,
the pvalue is not well-defined in this case, wouldn't it be better to
return NA or NaN or something?) Also,
2010 Feb 08
2
Incorrect Kendall's tau for ordered variables (PR#14207)
Full_Name: Marek Ancukiewicz
Version: 2.10.1
OS: Linux
Submission from: (NULL) (74.0.49.2)
Both cor() and cor.test() incorrectly handle ordered variables with
method="kendall", cor() incorrectly handles ordered variables for
method="spearman" (method="person" always works correctly, while
method="spearman" works for cor.test, but not for cor()).
In
2012 Jun 25
2
Fast Kendall's Tau
Hello.
Has any further action been taken regarding implementing David Simcha's fast Kendall tau code (now found in the package pcaPP as cor.fk) into R-base? It is literally hundreds of times faster, although I am uncertain as to whether he wrote code for testing the significance of the parameter. The last mention I have seen of this was in 2010
2004 Mar 03
1
cor(..., method="spearman") or cor(..., method="kendall") (PR#6641)
Dear R maintainers,
R is great. Now that I have that out of the way, I believe I have
encountered a bug, or at least an inconsistency, in how Spearman and
Kendall rank correlations are handled. Specifically, cor() and
cor.test() do not produce the same answer when the data contain NAs.
cor() treats the NAs as data, while cor.test() eliminates them. The
option
use="complete.obs" has
2011 Mar 21
1
Kendall v MannKendall Functions
Hi,
I am running a correlation analysis on a temporal dataset. I was wondering
if you would receive the same tau and p values running the function:
MannKendall(x), where x is the dependant variable that changes with time
as you would running:
Kendall(d,x), where x is the exact same dataset as the x entered into
MannKendall and d is the date on which the observation was made (assuming
that
2008 Apr 22
1
Comparing kendall's tau values?
I have 3 variables relating to the successful introductions of species
to 95 different areas: introduction frequency; number of successes pre
1906; number of successes post 1906
The data are not normal, nor homo-skedatic, so I am using non-parametric
statistics.
I have calculated Kendall's tau between both introduction & successes
pre 1906 (tau=0.3903) and introduction & successes
2011 Apr 30
1
Kendall's tau code
I discovered that the Kendall's tau calculation in R uses all pairwise comparisons which is O(n^2) and takes a long time for large vectors. I implemented a O(n*log(n)) algorithm based on merge-sort. Is this of interest to be included in core R? The code (fortran and R wrapper) is available in my package clinfun v0.9.7 (not exported in NAMESPACE).
Thanks,
Venkat
--
Venkatraman E. Seshan,
2009 May 13
0
Mann-Kendall test
Dear useRs,
I've been trying to run a Mann-Kendall test in my data in order to detect trends.
I studied the examples given at the Kendall package and I can understand pretty well how it works on time-series data.
However, my data consists of values in different sites per year, as I display below;
Year 1 | Year 2 | Year 3 | ...
Site 1 x x x ...
2002 Apr 25
3
Kendall's tau
A search of the archives did not reveal an answer:
For basic tests of association, where one has no a priori knowledge of the
form of the relation or of the distributions of the variables, rank
correlation seems like a good start. Why is cor.test() with Kendall and
Spearman options relegated to the ctest package, rather than in the base
package? Does this suggest that the developers consider
2006 Oct 02
0
Kendall for Copula
Somebody know what is the package in which I can find the association measures (like Kendall's Tau and Spearman's Rho) for a copula object (bivariate copulas)??
Thanks a lot.
Marta Di Lascio
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2011 Mar 28
0
Acessing Test Outputs for Writing to a Table
Hi all,
I am trying to write a script that will compute Kendall's tau for a 75 time
series (using the Kendall package) and will then write the tau and p values
from the Kendall test to a text file table that can be read into Excel.
I am having no problem calculating Kendall's tau and the associated p value
for each time series, but I am having trouble figuring out how aggregate the
2023 Nov 07
1
Concordance and Kendall's tau in copula
Dear
I estimate a sample selection model using the Clayton copula and Burr
and Gaussian marginal. I need to derive ther Kendall'sw tau from the
concordance coefficient by integration. I came across a way to do that
in R long time ago but cannot find it again. Can somewone tell me what
to read and what to use? Thank you.
Steven Yen
2007 Sep 06
3
kendall test
Hello,
I thougth that there is a function which does the kendall test in R,
I writed on the console apropos("kendall") and I didn't found anything can you tell me how could I do to use the kendall test?
Thanks.
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