Displaying 20 results from an estimated 5000 matches similar to: "Comparing of two non-normal distributions"
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
2010 Apr 19
2
Truncated Normal Distribution and Truncated Pareto distribution
Dear R helpers,
I have a bimodal dataset dealing with loss amounts. I have divided this dataset into two with the bounds for the first dataset i.e. dataset-A being 5,000$ to 100,000$ and the dataset-B deals with the losses exceeding 100,000$ i.e. dataset-B is left truncated.
I need to fit truncated normal disribution to dataset - I having lower bound of 5000 and upper bound of 100,000. While I
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 Feb 28
0
surv2sample 0.1-2
Dear useRs,
There is a new version 0.1-2 of the package surv2sample available on CRAN.
Users of the previous versions should update because a bug in the function
cif2.ks has been fixed.
General information about the package:
surv2sample provides various two-sample tests for right-censored survival
data. Three main areas and corresponding methods are:
* comparison of two survival
2008 Feb 28
0
surv2sample 0.1-2
Dear useRs,
There is a new version 0.1-2 of the package surv2sample available on CRAN.
Users of the previous versions should update because a bug in the function
cif2.ks has been fixed.
General information about the package:
surv2sample provides various two-sample tests for right-censored survival
data. Three main areas and corresponding methods are:
* comparison of two survival
2005 Sep 09
2
test for exponential,lognormal and gammadistribution
hello!
i don't want to test my sample data for normality, but exponential- lognormal-
or gammadistribution.
as i've learnt the anderson-darling-test in R is only for normality and i am
not supposed to use the kolmogorov-smirnov test of R for parameter estimates
from sample data, is that true?
can you help me, how to do this anyway!
thank you very much!
nadja
2009 Apr 12
1
goodness of fit between two samples of size N (discrete variable)
Hello list:
I generate by simulation (using different procedures) two sample vectors of size N, each corresponding to a discrete variable and I want to text if these samples can be considered as having the same probability distribution (which is unknown). What is the best test for that?
I've read that Kolmogorov-Smirnov and Anderson-Darling tests are restricted to continuous data
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'
2007 May 20
0
Testing multidimensional random numbers?
Dear Statistics-Experts,
Assume you have given a new and untested pseudo-random number
generator (prng) and you want to test if it "works". The distribution
function (cdf) from which the prng is supposed to sample is known.
Further, you are given some finite (large) sample from the prng. If
the sample is one-dimensional, we can apply the cdf to it and test
the sample for being
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)
2010 Jul 14
2
R's Data Dredging Philosophy for Distribution Fitting
Forum,
I'm a grad student in Civil Eng, took some Stats classes that required
students learn R, and I have since taken to R and use it for as much as I
can. Back in my lab/office, many of my fellow grad students still use
proprietary software at the behest of advisers who are familiar with the
recommended software (Statistica, @Risk (Excel Add-on), etc). I have spent
a lot of time learning
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 ....
>
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
2011 Jan 26
1
How to calculate p-value for Kolmogorov Smirnov test statistics?
Although I saw this issue being discussed many times before, I still
did not find the answer to:
why does R can not calculate p-values for data with ties (i.e. -
sample with two or more values the same)?
Can anyone elaborate some details about how does R calculate the p-
values for the Kolmogorov Smirnov test statistics?
I can understand the theoretical problem that continuous distributions
do
2008 Jun 26
1
lmer model with continuos non normal response variable, transformation needed?
Hi.
I want to do an lmer model but have doubts of what family I should use.
My response variable was originally a proportion, however I standarized it
for each year of data collection (20 in total). After standarizing it I
checked for normality with the Kolmogorov-Smirnov test, and it turns out
it is not normal. It ranges from -3 to 4.
Since it is no longer a proportion I can't use a
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,
2009 Apr 29
2
Kolmogorov-Smirnov test
I got a distribution function and a empirical distribution function. How do I
make to Kolmogorov-Smirnov test in R.
Lets call the empirical distribution function >Fn on [0,1]
and the distribution function >F on [0,1]
ks.test( )
thanks for the help
--
View this message in context: http://www.nabble.com/Kolmogorov-Smirnov-test-tp23296096p23296096.html
Sent
2000 Mar 01
2
Help please..
Hello R-world,
I am facing a peculiar problem and hope someone out there
can comment on it.
In goodness-of-fit tests for evaluation of distributions,
there are three well-known methods:
1. Chi-square
2. Anderson-Darling
3. Kolmogorov-Sminrov
I am trying to use the second test. Many researchers have
reported results using this test. I wrote programs in C and
now in R to do this. I run into
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
2002 Jul 01
1
modified kolmogorov-smirnov
I'm trying to use modified Kolmogorov-Smirnov test with a Normal which I
don't know it's parameters. Somebody told me about the lilifor function in
R, but just can't find it.
Does anybody know how I can test with the modified Kolmogorov-Smirnov
test?
Porqu? usar una base de datos relacional cualquiera,
si pod?s usar PostgreSQL?