Displaying 20 results from an estimated 2000 matches similar to: "PCA with spearman and kendall correlations"
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
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
2011 May 16
2
about spearman and kendal correlation coefficient calculation in "cor"
Hi,
I have the following two measurements stored in mat:
> print(mat)
[,1] [,2]
[1,] -14.80976 -265.786
[2,] -14.92417 -54.724
[3,] -13.92087 -58.912
[4,] -9.11503 -115.580
[5,] -17.05970 -278.749
[6,] -25.23313 -219.513
[7,] -19.62465 -497.873
[8,] -13.92087 -659.486
[9,] -14.24629 -131.680
[10,] -20.81758 -604.961
[11,] -15.32194 -18.735
To calculate the ranking
2009 Jan 24
1
Help with dudi.pca
Dear R-helpers,
I have two data frames, op and em4:
> str(op)
'data.frame': 37 obs. of 5 variables:
$ m : num 0.202 0.336 0.122 0.139 0.14 ...
$ lln : num 0.798 0.643 0.863 0.835 0.823 ...
$ rrn : num 0.789 0.702 0.894 0.895 0.923 ...
$ asym2: num 0.177 0.304 0.108 0.187 0.274 ...
$ asym3: num 0.0755 0.0975 0.0818 0.0651 0.13 ...
> str(rownames(op))
chr
2003 Jan 23
1
spearman rank correlation
hello help,
i''ve searched through the manual pages and the only reference i can find to spearman rank correlation is cor.test, which only seems to give the significance value of the correlation.
is there any way to get the actual value of rho?
david.
[[alternate HTML version deleted]]
2004 Mar 15
1
spearman rank correlation problem
Hello R gurus,
I want to calculate the Spearman rho between two ranked lists. I am
getting results with cor.test that differ in comparison to my own
spearman function:
> my.spearman
function(l1, l2) {
if(length(l1) != length(l2)) stop("lists must have same length")
r1 <- rank(l1)
r2 <- rank(l2)
dsq <- sapply(r1-r2,function(x) x^2)
1 - ((6 * sum(dsq))
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
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
2007 Mar 15
1
Incorrect matrix of spearman correlations .... in 64-bit Linux ... (PR#9568)
Full_Name: Vladimir Obolonkin
Version: tested in 2.0 to 2.4.1
OS: linux, win, mac
Submission from: (NULL) (202.14.96.194)
{{ Subject shortened manually -- to pass anti-spam filters
Original-subject: Incorrect matrix of spearman correlations working \
large (24000 by 425 and 78 by 425 data frames) in 64-bit Linux machines;\
the same code gives correct results in 32-bits Win and
2010 Apr 24
1
Multiple Correlation coefficient (spearman, Kenall)
Hi,
I'm currently trying to find/define a relationship between one dependent and
several independant variables.
The problem is that i cannot use the normal multiple regression/correlation
in Spss because the data is not normal distributed.
i calculated the spearman roh and Kendalls tau Correlation and also some
partial correlations in R.
Now i wanna find out the the multiple correlation
2006 Dec 05
1
Spearman correlation ties and discrepancies
Hi. I am currently trying to run some Spearman correlations, and have
encountered two issues.
1) When using cor.test() with a variable that includes ties, I get the
"Cannot compute exact p-values with ties" error. I have read that this
function now uses an asymptotic formula that allows for ties, so do not
understand why I am getting this error. (I am running version 2.4.0.)
I
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
2012 Aug 29
3
Help on calculating spearman rank correlation for a data frame with conditions
Dear all,
Suppose my data frame is as follows:
id price distance
1 2 4
1 3 5
...
2 4 8
2 5 9
...
n 3 7
n 8 9
I would like to calculate the rank-order correlation between price and
distance for each id.
cor(price,distance,method = "spearman") calculate a correlation for all.
Then I tried to use
apply(data,list='id',cor(price , distance , method =
2008 Feb 28
4
p-value in Spearman rank order
Dear R-helpers,
I would like to do a Spearman rank order test, and used the cor() function
with the method "spearman".
It gives me a number (correlation coefficient?) , but how can I get the
p-value?
Thank you for the help in advance!
Regards,
Anne-Katrin
--
[[alternative HTML version deleted]]
2004 Jul 31
1
dudi.pca behaviour and discrimin
Hello,
I not have attached in this e-mail the zipped
list of matrices I am using because it has 1 meg
once zipped and anyway we cannot send attached
files on r-help mailling list.
First, after running the code that is written
bellow, I realized that the printout of dudi.pca
gives me for both of my matrices
$cw length that are unequal to either respective $rank or $eig lengths.
Is that
2003 Nov 07
2
Bug in cor.test - Spearman
Greetings.
There seems to be a problem with the P-value computation in the
cor.test with method="spearman". In R1.8.0 (MS Windows) I
seem to be getting intermittently nonsense P-values, but the rho's
are OK. I can get this reproducibly with the toy example attached
where the first use is OK and subsequent calls with the same data
give nonsense. (I have also seen the problem
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",
2007 May 29
2
R's Spearman
Hi all,
I am trying to figure out the formula used by R's Spearman rho (using
cor(method="spearman")) because I can't seem to get the same value as by
calculating "by hand". Perhaps I'm using "cor" wrong, but I don't know
where. Basically, I am running these commands:
> y=read.table(file="tmp",header=TRUE,sep="\t")
>
2002 Apr 26
2
Spearman Correlation
Hi all,
Is there a convenient way to calculate Spearman correlation coefficients in
R?
Nick
Nianqing Xiao, Ph.D
NCI Center for Bioinformatics, NIH
SAIC/Advanced Systems Group
> 6116 EXECUTIVE BLVD 4026J
> MSC 8335
> BETHESDA MD 20852
Phone: 301-451-6357
Fax: 301-480-4222
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read
2008 Sep 10
3
making spearman correlation cor() call fail with log(0) as input
Hi,
How can I make the cor(x, y, method="spearman") call to produce an
error when the input to it (x, y) produces an error? Here is a simple
example:
> a <- c(0, 1, 2)
> b <- c(100, 2, 4)
## error:
> log(a)
[1] -Inf 0.0000000 0.6931472
## error, as expected:
> cor(log(a), log(b), method="pearson")
[1] NaN
## not an error any more (not expected):
>