Displaying 20 results from an estimated 100000 matches similar to: "KS Test questions"
2009 Jul 22
0
ks.test - The two-sample two-sided Kolmogorov-Smirnov test with ties (PR#13848)
Full_Name: Thomas Waterhouse
Version: 2.9.1
OS: OS X 10.5.7
Submission from: (NULL) (216.239.45.4)
ks.test uses a biased approximation to the p-value in the case of the two-sample
test with ties in the pooled data. This has been justified in R in the past by
the argument that the KS test assumes a continuous distribution. But the
two-sample test can be extended to arbitrary distributions by a
2024 Apr 07
0
Questions about ks.test function {stats}
Dear R-help,
Hope this email finds you well. My name is Ziyan. I am a graduate student in Zhejiang University. My subject research involves ks.test in stats-package {stats}. Based on the code, I have two main questions. Could you provide me some more information?
I download different versions of the r language source code through r language website (https://www.r-project.org/). By reading
2010 Aug 04
4
KS Test question (2)
Hi R Users,
I have two vectors, x and y, of equal length representing two types of
data from two studies. I would like to test if they are similar enough
to use them interchangeably. No assumptions about distributions can be
made (initial tests clearly show that they are not normal).
Here some result:
Two-sample Kolmogorov-Smirnov test
data: x and y
D = 0.1091, p-value < 2.2e-16
alternative
2005 Jun 27
1
ks.test() output interpretation
I'm using ks.test() to compare two different
measurement methods. I don't really know how to
interpret the output in the absence of critical value
table of the D statistic. I guess I could use the
p-value when available. But I also get the message
"cannot compute correct p-values with ties ..." does
it mean I can't use ks.test() for these data or I can
still use the D
2001 Jul 01
0
ks.test doesn't compute correct empirical distribution if there are ties in the data (PR#1007)
Full_Name: Andrew Grant McDowell
Version: R 1.1.1 (but source in 1.3.0 looks fishy as well)
OS: Windows 2K Professional (Consumer)
Submission from: (NULL) (194.222.243.209)
In article <xeQ_6.1949$xd.353840@typhoon.snet.net>,
johnt@tman.dnsalias.com writes
>Can someone help? In R, I am generating a vector of 1000 samples from
>Bin (1000, 0.25). I then do a Kolmogorov Smirnov test
2001 Jul 03
0
(PR#1007) ks.test doesn't compute correct empirical distribution if there are ties in the data
In message <Pine.GSO.4.31.0107010731110.7616-100000@auk.stats>, Prof
Brian D Ripley <ripley@stats.ox.ac.uk> writes
>
>You do realize that the Kolmogorov tests (and the Kolmogorov-Smirnov
>extension) assume continuous distributions, so the distribution theory
>is not valid in this case?
>
>S-PLUS does stop you doing this:
>
>> ks.gof(o,
2000 Apr 27
0
What is ks.test saying?
Hello!
I have two matrices of equal dimension ll and lu that I want to do a
ks.test on corresponding rows in these matrices (dim(ll) is [1] 101 100).
If I do e.g. > ks.test(ll[50,],lu[50,])
just for testing, it displays a lot of numbers, and some more info:
[116] -3.000000e-02 -4.000000e-02 -4.000000e-02 -3.000000e-02 -4.000000e-02
[121] -3.000000e-02 -4.000000e-02 -3.000000e-02 -2.000000e-02
2008 Mar 08
1
ks.test troubles
Hi there!
I have two little different data. One is a computer test on people, the
other is a paper and pencil test. two boxplots show me that the data is
almost the same.
So now I'd like to know if I could handle all data as one, by testing
with ks.test:
====
> ks.test(el$angststoer, fl$angststoer)
Two-sample Kolmogorov-Smirnov test
data: el$angststoer and fl$angststoer
D =
2004 Nov 04
0
(no subject)-about the waring/errors in ks.test
[In future, please press reply all as there might be others in the
mailing list who can help you]
Without a (short) reproducible example, it would be difficult to say.
BTW, I think you have mistyped the error/warning message. Does it
actually say "cannot compute _correct_ p-value" or "cannot compute
_exact_ p-value". See example below.
> wilcox.test( 1:3, 1:10 )
2010 Aug 20
3
how to interpret KS test
Dear R users
I am using KS test to compare two different distribution for the same
variable (temperature) for two different time periods.
H0: the two distributions are equal
H1: the two distributions are different
ks.test (temp12, temp22)
Two-sample Kolmogorov-Smirnov test
data: temp12 and temp22
D = 0.2047, p-value < 2.2e-16
alternative hypothesis: two-sided
Warning message:
In
2004 Nov 01
1
ks.test calculations incorrect (PR#7330)
Full_Name: t. avery
Version: 2.0.0
OS: windows xp / Linux
Submission from: (NULL) (131.162.134.159)
ks.test does not produce the correct output.
If given the script:
d1 <- c(53.63984674,0.383141762,1.915708812,0.383141762,10.72796935,6.896551724,20.30651341,5.747126437,0)
d1
d2 <- c(76.43312102,15.2866242,3.821656051,1.27388535,0,0.636942675,1.27388535,0.636942675,0.636942675)
d2
2002 Mar 26
3
ks.test - continuous vs discrete
I frequently want to test for differences between animal size frequency
distributions. The obvious test (I think) to use is the Kolmogorov-Smirnov
two sample test (provided in R as the function ks.test in package ctest).
The KS test is for continuous variables and this obviously includes length,
weight etc. However, limitations in measuring (e.g length to the nearest
cm/mm, weight to the nearest
2023 Apr 21
1
Confusion about ks.test() handling of ties and exact vs approximate results
Hello,
Today I was investigating ks.test() with two numerical arguments (x and y) and was left a bit confused about the policy behind handling ties.
I might be missing something, so sorry in advance, but here is what confuses me:
The documentation states: "The presence of ties always generates a warning, since continuous distributions do not generate them"
But when I run a test with
2006 Jul 09
1
KS Test Warning Message
All,
Happy World Cup and Wimbledon. This morning finds me with the first
of my many daily questions.
I am running a ks.test on residuals obtained from a regression model.
I use this code:
> ks.test(Year5.lm$residuals,pnorm)
and obtain this output
One-sample Kolmogorov-Smirnov test
data: Year5.lm$residuals
D = 0.7196, p-value < 2.2e-16
alternative hypothesis: two.sided
Warning
2001 Jul 01
1
(PR#1007) ks.test doesn't compute correct empirical
On Sun, 1 Jul 2001 mcdowella@mcdowella.demon.co.uk wrote:
> Full_Name: Andrew Grant McDowell
> Version: R 1.1.1 (but source in 1.3.0 looks fishy as well)
> OS: Windows 2K Professional (Consumer)
> Submission from: (NULL) (194.222.243.209)
Please upgrade: we've found a number of Win2k bugs and worked around them
since then, let alone teh bug fixes and improvements in R ....
>
2007 Jan 14
2
ks.test not working?
Hi,
I am trying the following:
library(ismev)
library(evd)
fit <- gev.fit(x,show=FALSE)
ks.test(x,pgev,fit$mle[1],fit$mle[2],fit$mle[3])
but I am getting:
Warning message:
cannot compute correct p-values with ties in: ks.test(x, pgev,
fit$mle[1], fit$mle[2], fit$mle[3])
where x is:
[1] 239 38 1 43 22 1 5 9 15 6 1 9 156
25 3 100 6
[18] 5 100
2009 Sep 08
1
Unexpected behavior in friedman.test and ks.test
I have to start by saying that I am new to R, so I might miss something crucial here. It seems to me that the results of friedman.test and ks.test are "wrong". Now, obviously, the first thing which crossed my mind was "it can't be, this is a package used by so many, someone should have observed", but I can't figure out what it might be.
Problem: let's start with
1999 Apr 09
2
KS test from ctest package
This question is mainly aimed at Kurt Hornik as author of the ctest package,
but I'm cc'ing it to r-help as I suspect there will be other valuable
opinions out there.
I have been attempting 2 sample Kolmogorov-Smirnov tests using the ks.test
function from the ctest package (ctest v.0.9-15, R v.0.63.3 win32). I am
comparing fish length-frequency distributions. My main reference for the
2006 Jun 16
0
The qurey about kolmogorov-smirnov test & adding the trendline to graph
I am hereby forwarding the data & method use to calculate the
Kolmogorov-Smirnov goodness of fit test made manually by me in R
launguage which deffers with the actual inbuilt formula as shown below.
Further I have plot the graph in R. In that graph how to add trendline
(i.e. straight line passing through maximum points in plot) to a Plot.
R script is as follows please run this script to see
2006 Mar 22
1
Modified KS test to handle ties.
Dear All,
I wonder if there is now an implementation of a modified KS test that
can handle ties?
Steve.
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