Displaying 20 results from an estimated 7000 matches similar to: "ks.test - continuous vs discrete"
2003 Aug 28
2
ks.test()
Dear All
I am trying to replicate a numerical application (not computed on R) from an
article. Using, ks.test() I computed the exact D value shown in the article
but the p-values I obtain are quite different from the one shown in the
article.
The tests are performed on a sample of 37 values (please see "[0] DATA"
below) for truncated Exponential, Pareto and truncated LogNormal
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 Feb 03
2
Problems with ks.test
Hi everybody,
while performing ks.test for a standard exponential distribution on samples
of dimension 2500, generated everytime as new, i had this strange behaviour:
>data<-rexp(2500,0.4)
>ks.test(data,"pexp",0.4)
One-sample Kolmogorov-Smirnov test
data: data
D = 0.0147, p-value = 0.6549
alternative hypothesis: two.sided
>data<-rexp(2500,0.4)
2011 Jun 10
3
Test if data uniformly distributed (newbie)
Hello,
I have a bunch of files containing 300 data points each with values from 0
to 1 which also sum to 1 (I don't think the last element is relevant
though). In addition, each data point is annotated as an "a" or a "b".
I would like to know in which files (if any) the data is uniformly
distributed.
I used Google and found out that a Kolmogorov-Smirnov or a Chi-square
2011 Oct 06
2
KS test and theoretical distribution
> x <- runif(100)
> y <- runif(100)
> ks.test(x,y)
Two-sample Kolmogorov-Smirnov test
data: x and y
D = 0.11, p-value = 0.5806
alternative hypothesis: two-sided
ok I expected that, but:
> ks.test(runif(100), "runif")
One-sample Kolmogorov-Smirnov test
data: runif(100)
D = 0.9106, p-value < 2.2e-16
alternative hypothesis: two-sided
How
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 ....
>
2005 Mar 18
1
Pb with ks.test pvalue
Hello,
While doing test of normality under R and SAS, in order to prove the efficiency of R to my company, I notice
that Anderson Darling, Cramer Van Mises and Shapiro-Wilk tests results are quite the same under the two environnements,
but the Kolmogorov-smirnov p-value really is different.
Here is what I do:
> ks.test(w,pnorm,mean(w),sd(w))
One-sample Kolmogorov-Smirnov test
data: w
D
2003 Sep 15
1
question regarding ks.test()
Hi,
I'm using the ks.test() on two vectors. I looked up the reference and
also coded up a version of the two sample Smirnov test. My question is
that how can I decide from the output of R that the two vectors x & y
come from the same distribution?
Am I correct in assuming that smaller D values indicate that they come
from the same distribution? In addition how can I use the p value that
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
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 =
2006 May 26
2
multiple comparisons of time series data
I am interested in a statistical comparison of multiple (5) time series'
generated from modeling software (Hydrologic Simulation Program Fortran). The
model output simulates daily bacteria concentration in a stream. The multiple
time series' are a result of varying our representation of the stream within
the model.
Our main question is: Do the different methods used to represent a
2007 Nov 16
2
ks.test
Hello,
I want to do normality test on my data
I write this but I don't understand the display of the results
ks.test(data,"pnorm")
In fact I want to know if my data is a normal distribution. I have to check the p-value or D?
Thanks.
_____________________________________________________________________________
l
[[alternative HTML version deleted]]
2006 May 09
4
ks.test one-sample - where can I get a list of the strings specifying the distribution?
Dear all,
One can use ks.test(x,y) for a one-sample kolmogorov-smirnov test:
x being the data sample
y being a string specifying a distribution
I notice the help on ks.test does not tell you how to get such a list. Is
this a hole in my R knowledge?
Where can I get a list of the strings specifying the possible
distributions?
and more specifically
What would be the string and following
2011 Oct 13
1
KS test
Hi!
how can I do the Kolmogorov Smirnov test for discrepancy between the
estimated and empirical tails?
Regards
Anuradha
[[alternative HTML version deleted]]
2005 Jan 11
3
Kolmogorov-Smirnof test for lognormal distribution with estimated parameters
Hello all,
Would somebody be kind enough to show me how to do a KS test in R for a
lognormal distribution with ESTIMATED parameters. The R function
ks.test()says "the parameters specified must be prespecified and not
estimated from the data" Is there a way to correct this when one uses
estimated data?
Regards,
Kwabena.
--------------------------------------------
Kwabena Adusei-Poku
2001 Jun 29
1
KS test in R.1.3.0 has incorrect p-values. (PR#1004)
Based on a report to the Windows maintainers from Richard Rowe
<Richard.Rowe@jcu.edu.au>:
NEWS for 1.3.0 says
o Exact p-values are available for the two-sided two-sample
Kolmogorov-Smirnov test.
I think the (new) p-values are computed but are backwards:
> set.seed(123)
> x <- rnorm(50)
> y <- runif(50)
> ks.test(x,y, exact=T)$p
[1] 1
> 1 - ks.test(x,y,
2005 Jun 27
1
ks.test() output interpretation
I'm using ks.test() to compare two different
measurement methods. I don't really know how to
interpret the output in the absence of critical value
table of the D statistic. I guess I could use the
p-value when available. But I also get the message
"cannot compute correct p-values with ties ..." does
it mean I can't use ks.test() for these data or I can
still use the D
2004 Nov 01
1
ks.test calculations incorrect (PR#7330)
Full_Name: t. avery
Version: 2.0.0
OS: windows xp / Linux
Submission from: (NULL) (131.162.134.159)
ks.test does not produce the correct output.
If given the script:
d1 <- c(53.63984674,0.383141762,1.915708812,0.383141762,10.72796935,6.896551724,20.30651341,5.747126437,0)
d1
d2 <- c(76.43312102,15.2866242,3.821656051,1.27388535,0,0.636942675,1.27388535,0.636942675,0.636942675)
d2
2001 Oct 26
1
ks.test (PR#1004)
The note to 1004 says "fixed for 1.3.1"
Uh. No. It ain't.
The problem was more serious than guessed as even the simplest testing
would show.
For example, Example 5.4 in Hollander and Wolfe (Nonparametric Statistical,
Methods, 2nd ed., Wiley, 1999, pp. 180-181)
R Version 1.3.1 (SuSE Linux 7.1)
> X <-
2006 Jul 09
1
KS Test Warning Message
All,
Happy World Cup and Wimbledon. This morning finds me with the first
of my many daily questions.
I am running a ks.test on residuals obtained from a regression model.
I use this code:
> ks.test(Year5.lm$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