Displaying 20 results from an estimated 8000 matches similar to: "Measure Difference Between Two Distributions"
2001 Nov 10
2
Goodness-of-fit on Burr distributed data
I simulate a uniform data and then transformed into Burr(1,3,1) data,
which is of pdf:
f(x)=[3*(x^2)] / [(1+x^3)^2], x>0
How can I perform a goodness-of-fit test (k-s,
anderson-darling,chisq,cramer-von mises,...) on it (should highly accept)
to get test-statistics & p-values?
Thanks!
Sincerely,
Shelton Jin
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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
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
2012 Jul 30
3
curve comparison
Dear R users,
I have seven regression lines I´d like to compare, in order to find out if
these are significatively different. The main problem is that these are
curves, non normal, non homogeneous data, I´ve tried to linearize them but
it has not worked. So I´d like to know if you know any command or source in
R which explains how to perform this kind of comparison.
Thanks in advance for your
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
2009 May 28
3
R help
Dear Sir
I am new user of R.
I am interested in modeling hydrological extreme events. I found MSClaio2008 very interesting function. In this function four criterions for choosing distributions. Can we call these criterions as model selection techniques or goodness of fit techniques or both? Because goodness of fit techniques are usually performed after modle selection.
Can I found
2012 Nov 13
1
Simulation with cpm package
Hi,
I am running the following code based on the cpm vignette's code. I believe
the code is syntactically correct but it just seems to hang R. I can get
this to run if I set the sims to 100 but with 2000 it just hangs. Any ideas
why?
Thanks,
Chris
library(cpm)
cpmTypes <- c("Kolmogorov-Smirnov","Mann-Whitney","Cramer-von-Mises")
changeMagnitudes <- c(1, 2,
2008 Oct 26
2
Two sample Cramer-von Mises test
Hall all,
Where can I find the two sample Cramer-von Mises test in R package?
Thank you.
Legendy
--
View this message in context: http://www.nabble.com/Two-sample-Cramer-von-Mises-test-tp20174229p20174229.html
Sent from the R help mailing list archive at Nabble.com.
2012 Nov 24
2
Comparing the Means of Two Normal Distributions
Dear All,
A problem almost taken from a textbook: I have two independent samples
(which are both assumed to come from a normal distribution).
The sample sizes are N1 and N2, the sample means are x1 and x2 and the
sample standard deviations are s1 and s2 (the standard deviations are
close).
I would like to conduct a two sample t-test with equal variances at
alpha=0.05 (and then remove the
2004 Apr 14
7
trend turning points
Hi,
does anybody know of a nice test to detect trend turning points in time
series? Possibly with reference?
Thanks,
joerg
2006 Jun 12
2
Fitting Distributions Directly From a Histogram
Dear All,
A simple question: packages like fitdistr should be ideal to analyze
samples of data taken from a univariate distribution, but what if
rather than the raw data of the observations you are given directly
and only a histogram?
I was thinking about generating artificially a set of data
corresponding to the counts binned in the histogram, but this sounds
too cumbersome.
Another question is
2017 Nov 07
2
Fitdistrplus and Custom Probability Density
Dear All,
Apologies for not providing a reproducible example, but if I could, then I
would be able to answer myself my question.
Essentially, I am trying to fit a very complicated custom probability
distribution to some data.
Fitdistrplus does in principle everything which I need, but if require me
to specify not only the density function d, but also the cumulative p and
and inverse cumulative
2019 Jul 09
3
[R] Curl4, Quantmod, tseries and forecast
Hi Ralf,
I tried the following
> install.packages("RCurl")
which went OK, but then same story when I tried to install tseries.
> sessionInfo()
R version 3.6.1 (2019-07-05)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Debian GNU/Linux 10 (buster)
Matrix products: default
BLAS: /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.8.0
LAPACK:
2013 Mar 24
3
Parallelizing GBM
Dear All,
I am far from being a guru about parallel programming.
Most of the time, I rely or randomForest for data mining large datasets.
I would like to give a try also to the gradient boosted methods in GBM,
but I have a need for parallelization.
I normally rely on gbm.fit for speed reasons, and I usually call it this
way
gbm_model <- gbm.fit(trainRF,prices_train,
offset = NULL,
misc =
2013 Feb 09
3
Addressing Columns in a Data Frame
Dear All,
Probably a one liner, but I am banging my head against the floor.
Consider the following
DF <- data.frame(
x=1:10,
y=10:1,
z=rep(5,10),
a=11:20
)
mn<-names(DF)
but then I cannot retrieve a column by doing e.g,
DF$mn[2]
I tried to play with the quotes and so on, but so far with no avail.
Any suggestion is welcome.
Cheers
Lorenzo
2009 Jan 26
1
Goodness of fit for gamma distributions
I'm looking for goodness of fit tests for gamma distributions with large data
sizes. I have a matrix with around 10,000 data values in it and i have
fitted a gamma distribution over a histogram of the data.
The problem is testing how well that distribution fits. Chi-squared seems to
be used more for discrete distributions and kolmogorov-smirnov seems that
large sample sizes make it had to
2010 Oct 24
6
Contour Plot on a non Rectangular Grid
Dear All,
I would like to plot a scalar (e.g. a temperature) on a non-rectangular
domain (or even better: I would simply like to be able to draw a contour
plot on an arbitrary 2D domain). I wonder if there is any tool to
achieve that with R. I did some online search in particular on the list
archives, found several queries similar to this one but was not able to
find any conclusive answer.
I
2009 Jul 20
3
Histograms on a log scale
Dear All,
I would like to be able to plot histograms/densities on a semi-log or
log-log scale.
I found several suggestions online
http://tolstoy.newcastle.edu.au/R/help/05/09/12044.html
https://stat.ethz.ch/pipermail/r-help/2002-June/022295.html
http://www.harding.edu/fmccown/R/#histograms
Now, consider the code snippet taken from
http://www.harding.edu/fmccown/R/#histograms
# Get a random
2011 Dec 15
3
From Distance Matrix to 2D coordinates
Dear All,
I am struggling with the following problem: I am given a NxN symmetric
matrix P ( P[i,i]=0, i=1...N and P[i,j]>0 for i!=j) which stands for the
relative distances of N points.
I would like use it to get the coordinates of the N points in a 2D
plane. Of course, the solution is not unique (given one solution, I can
translate or rotate all the points by the same amount and generate
2009 May 20
1
Comparing spatial distributions - permutation test implementation
Hello everyone,
I am looking at the joint spatial distribution of 2 kinds of organisms
(estimated on a grid of points) and want to test for significant
association or dissociation.
My first question is: do you know a nice technique to do that,
considering that I have a limited number of points (36) but that they
are repeated (4 times)? I did GLMs to test for correlations between
the