Displaying 20 results from an estimated 3000 matches similar to: "KS test and theoretical distribution"
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)
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
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
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 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
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
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 ....
>
2011 Feb 19
3
Kolmogorov-smirnov test
Is the kolmogorov-smirnov test valid on both continuous and discrete data?
I don't think so, and the example below helped me understand why.
A suggestion on testing the discrete data would be appreciated.
Thanks,
a <- rnorm(1000, 10, 1);a # normal distribution a
b <- rnorm(1000, 12, 1.5);b # normal distribution b
c <- rnorm(1000, 8, 1);c # normal distribution c
d <- rnorm(1000,
2011 Apr 27
3
Kolmogorov-Smirnov test
Hi,
I have a problem with Kolmogorov-Smirnov test fit. I try fit distribution to
my data. Actualy I create two test:
- # First Kolmogorov-Smirnov Tests fit
- # Second Kolmogorov-Smirnov Tests fit
see below. This two test return difrent result and i don't know which is
properly. Which result is properly? The first test return lower D = 0.0234
and lower p-value = 0.00304. The lower 'D'
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
2011 Jul 29
1
How to interpret Kolmogorov-Smirnov stats
Hi,
Interpretation problem ! so what i did is by using the:
>fit1 <- fitdist(vectNorm,"beta")
Warning messages:
1: In dbeta(x, shape1, shape2, log) : NaNs produced
2: In dbeta(x, shape1, shape2, log) : NaNs produced
3: In dbeta(x, shape1, shape2, log) : NaNs produced
4: In dbeta(x, shape1, shape2, log) : NaNs produced
5: In dbeta(x, shape1, shape2, log) : NaNs produced
6: In
2007 Oct 03
3
P-value
Hi,
why don't you try try
ks.test(VeriSeti1, VeriSeti2)$p.value
All the best
Jenny
>How can i print only the P-Value of the kolmogorov smirnov test?
>
>
>> ks.test(VeriSeti1, VeriSeti2)
>
> Two-sample Kolmogorov-Smirnov test
>
>data: VeriSeti1 and VeriSeti2
>D = 0.5, p-value = 0.4413
>alternative hypothesis: two-sided
>
>
>This expression
2009 Sep 20
3
plotting least-squares regression against x-axis
Hi,
I want to plot the residuals of a least-squares regression.
plot(lm(y~x), which=1)
does this, but it plots the y-axis of my data on the x-axis of the
residuals plot. That is, it plots the residual for each y-value in the
data. Can I instead use the x-axis of my data as the x-axis of the
residuals plot, showing the residual for a given x?
Thanks!
Jason Priem
University of North
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 <-
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]]
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
2009 Oct 12
1
Kolmogorov smirnov test
Hi r-users,
I would like to use Kolmogorov smirnov test but in my observed data(xobs) there are ties. I got the warning message. My question is can I do something about it?
ks.test(xobs, xsyn)
Two-sample Kolmogorov-Smirnov test
data: xobs and xsyn
D = 0.0502, p-value = 0.924
alternative hypothesis: two-sided
Warning message:
In ks.test(xobs, xsyn) : cannot compute correct
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,
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
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