Displaying 20 results from an estimated 1000 matches similar to: "Kolmogorov-Smirnof test for lognormal distribution with estimated parameters"
2004 Nov 03
1
Kernel Density estimation - locfit package
Hello there,
I am presently using the locfit package in "R" and would appreciate some
help here. Could anyone tell me tell me how I can obtain the various
components (x and y values)of the density estimation after using the "R"
command "locfit"? For example, with the command
"fhat<-density(somename)" I can obtain the x and y values by simply
calling
2007 Jul 04
2
probabilty plot
Hi all,
I am a freshman of R,but I am interested in it! Those days,I am
learning pages on NIST,with url
http://www.itl.nist.gov/div898/handbook/eda/section3/probplot.htm,
I am meeting a problem about probability plot and I don't know how to
plot a data set with R.
Could somebody tell me the answer,and a example is the best! I will
look forward to your answer.
Thank you very much.
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
2006 Apr 07
3
finding common elements in a list
Suppose I have a list where I want to extract only the elements that occur
in every component. For instance in the list foo I want to know that the
numbers 2 and 3 occur in every component. The solution I have seems
unnecessarily clunky. TIA, Andy
foo <- list(x = 1:10, y=2:11, z=1:3)
bar <-unlist(foo)
bartab <- table(bar)
as.numeric(names(bartab)[bartab==length(foo)])
2009 May 29
1
Mean of lognormal in base-2
Hi, Does anyone know what the mean value of a lognormal distribution in base-2 is? I am simulating stochastic population growth and if I were working in base-e, I would do:lambda <- 1.1 #multiplicative growth rates <- 0.6 #stochasticity (std. dev)lognormal <- rlnorm(100000, log(lambda) - (s^2)/2, s)## or lognormal <- exp( rnorm( 100000, log(lambda) - (s^2)/2,
2007 Sep 07
1
How to obtain parameters of a mixture model of two lognormal distributions
Dear List,
I have read that a lognormal mixture model having a pdf of the form
f(x)=w1*f1(x)+(1-w1)*f2(x) fits most data sets quite well, where f1
and f2 are lognormal distributions.
Any pointers on how to create a function that would produce the 5
parameters of f(x) would be greatly appreciated.
> version
_
platform i386-pc-mingw32
arch i386
os
2006 Aug 05
1
AIC for lognormal model
Dear all,
I want to compare some different models for a dataset by QQ plots and AIC. I get the following AICs:
- linear model: 19759.66
- GAMLSS model: 18702.7
- linear model with lognormal response: -7862.182
The QQ plots show that the lognormal model fits better than the linear model, but still much worse than the GAMLSS. So, in my opinion, the AIC of the lognormal model should be between the
2007 Mar 23
1
generating lognormal variables with given correlation
Dear R users
I use simulated data to evaluate a model by sampling the parameters in
my model from lognormal distributions.
I would like these (lognormal distributed) parameters to be correlated,
that is, I would like to have pairwise samples of 2 parameters with a
given correlation coefficient.
I have seen that a covariance matrix can be fixed when generating random
variables from a
2010 Dec 27
3
Gamma & Lognormal Model
Dear,
I'm very new to R Gui and I have to make an assignment on Gamma Regressions.
Surfing on the web doesn't help me very much so i hope this forum may be a
step forward.
The question sounds as follows:
The data set is in the library MASS
first install library(MASS)
then type data(mammals)
attach(mammals)
Assignment:
Fit the gamma model and lognormal model for the mammals data.
2010 Aug 01
2
Lognormal distribution - Range Factor
Hi, What does it mean to say Lognormal distribution with a mean of 1.03E-6
with a range factor of 100 ? How can I find the lognormal distribution
paramters from this information?
Thanks, Tims
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2011 Nov 01
1
low sigma in lognormal fit of gamlss
Hi,
I'm playing around with gamlss and don't entirely understand the sigma
result from an attempted lognormal fit.
In the example below, I've created lognormal data with mu=10 and sigma=2.
When I try a gamlss fit, I get an estimated mu=9.947 and sigma=0.69
The mu estimate seems in the ballpark, but sigma is very low. I get similar
results on repeated trials and with Normal and
2010 Mar 26
1
Poisson Lognormal
Hi R Users,
I'm going to estimate via. ML the parameters in Poisson Lognormal
model. The model is:
x | lambda ~ Poisson(lambda)
lambda ~ Lognormal(a,b)
Unfortunately, I haven't found a useful package allowing for such
estimation. I tried to use "poilog" package, but there is no equations
and it's hard to understand what exactly this package really does.
Using it I get the
2002 Dec 10
1
Lognormal distribution
I am trying to fit a lognormal distribution to a set of data and test its
goodness of fit with regard to predicted values.
I managed to get so far:
> y <- c(2,6,2,3,6,7,6,10,11,6,12,9,15,11,15,8,9,12,6,5)
> library(MASS)
> fitdistr(y,"lognormal",start=list(meanlog=0.1,sdlog=0.1))
meanlog sdlog
1.94810515 0.57091032
(0.12765945) (0.09034437)
But I would
2008 Jul 17
0
How to compute loglikelihood of Lognormal distribution
Hi,
I am trying to learn lognormal mixture models with EM.
I was wondering how does one compute the log likelihood.
The current implementation I have is as follows,
which perform really bad in learning the mixture models.
__BEGIN__
# compute probably density of lognormal.
dens <- function(lambda, theta, k){
temp<-NULL
meanl=theta[1:k]
sdl=theta[(k+1):(2*k)]
2004 May 01
2
Generating Lognormal Random variables (PR#6843)
Full_Name: Anthony Gichangi
Version: 1.90
OS: Windows XP Pro
Submission from: (NULL) (130.225.131.206)
The function rlnorm generates negative values for lognormal distribution.
x- rlnorm(1000, meanlog = 0.6931472, sdlog = 1)
Regards
Anthony
2005 Sep 27
1
Producing empirical bayes estimates in disease mapping for lognormal model
I'm trying to produce empirical bayes estimates based on the lognormal
model in disease mapping
Is there a way this can be done in R?
thanks
Oarabile
2008 Feb 15
0
tests of lognormal distribution
Hi all,
I have a data of lognormal distribution (sample size > 1,000,000).
What I want to do is
1) to test if my dataset is a lognormal distribution or not (Histogram shows
a nice normal distribution in log scale but I want to check)
2) two subsets from this dataset have same mean or not (like "t test" of
normal distribution)
What I tried are
1) ad.test{truncgof} of R, which is a
2012 Jun 19
1
3-D plot of a bidimensional lognormal distribution
Hi and thanks in advance to everyone who will be able to help me.
I have 2 independent lognormal distributions with different means and sd. I
want to plot them togheter in a 3D plot.
How can i do this??? I'm getting crazy...
Thanks
Ale
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2004 Dec 13
1
AIC, glm, lognormal distribution
I'm attempting to do model selection with AIC, using a glm and a lognormal
distribution, but:
fit1<-glm(BA~Year,data=pdat.sp1.65.04, family=gaussian(link="log"))
## gives the same result as either of the following:
fit1<-glm(BA~Year,data=pdat.sp1.65.04, family=gaussian)
fit1<-lm(BA~Year,data=pdat.sp1.65.04)
fit1
#Coefficients:
#(Intercept) Year2004
# -1.6341
2003 Apr 09
3
plotting the lognormal density curve
I am trying to plot a lognormal density curve on top of an existing
histogram. Can anybody suggest a simple way to do this? Even if someone
could just explain how to plot a regular normal density curve on top of an
existing histogram, it would be a big help.
Also, is there some way to search through the R-help archives other than
simple browsing?
Thank you so much. Your help and time is greatly