Displaying 20 results from an estimated 300 matches similar to: "Test K-S con distribuciones LogNormales"
2007 Nov 14
2
Generating log transformed random numbers
Dear R users,
My question is that how it is possible to generate some random numbers using rnorm( ) function but in log transformed values.
Thank you,
Tobias
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2008 Feb 18
0
Solved (??) Behaviour of integrate (was 'Poisson-lognormal probab ility calculations')
Hi Again,
I think I've solved my problem, but please tell me if you think I'm wrong,
or you can see a better way!
A plot of the integrand showed a very sharp peak, so I was running into the
integrand "feature" mentioned in the note. I resolved it by limiting the
range of integration as shown here:
--------------------------------------------------
function (x, meanlog = 0,
2008 Feb 15
0
Behaviour of integrate (was 'Poisson-lognormal probability calcul ations')
Hi again,
Adding further information to my own query, this function gets to the core
of the problem, which I think lies in the behaviour of 'integrate'.
-------------------------------------
function (x, meanlog = 0, sdlog = 1, ...) {
require(stats)
integrand <- function(t, x, meanlog, sdlog) dpois(x,t)*dlnorm(t,
meanlog, sdlog)
mapply(function(x, meanlog, sdlog, ...)
#
2008 Feb 15
0
Poisson-lognormal probability calculations
Hi,
just for the record, although I don't think it's relevant (!)
-------------------------------------
> sessionInfo()
R version 2.6.0 (2007-10-03)
i386-pc-mingw32
locale:
LC_COLLATE=English_United Kingdom.1252;LC_CTYPE=English_United
Kingdom.1252;LC_MONETARY=English_United
Kingdom.1252;LC_NUMERIC=C;LC_TIME=English_United Kingdom.1252
attached base packages:
[1] stats4 splines
2013 May 10
1
rlnorm(n, meanlog = 0, sdlog = 1)
Hi list,
Does anyone know the code behind rlnorm(n, meanlog = 0, sdlog = 1)? I am
going to write it in c#.
thanks
Alireza
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2010 Apr 28
0
Truncated Lognormal Distribution
Hi!
I have following data which is left truncated say at 10. I am trying to estimate the parameters of the Truncated Lognormal distribution to this data as given below.
(I have referred to R code appearing in an earlier post - http://finzi.psych.upenn.edu/Rhelp10/2008-October/176136.html)
library(MASS)
x <- c(600.62,153.05,70.26,530.42,3440.29,97.45,174.51,168.47, 116.63,36.51, 219.77,
2003 Jul 25
5
named list 'start' in fitdistr
Hi R lovers!
I'd like to know how to use the parameter 'start' in the function
fitdistr()
obviously I have to provide the initial value of the parameter to optimize
except in the case of a certain set of given distribution
Indeed according to the help file for fitdistr
" For the following named distributions, reasonable starting values
will be computed if `start'
2008 May 04
1
Is my understanding of rlnorm correct?
rlnorm takes two 'shaping' parameters: meanlog and sdlog.
meanlog would appear from the documentation to be the log of the mean.
eg if the desired mean is 1 then meanlog=0.
So to generate random values that fit a lognormal distribution I would
do this:
rlnorm(N , meanlog = log(mean) , sdlog = log(sd))
But when I check the mean I don't get it when sdlog>0. Interestingly I
2002 Jul 12
1
Minor bug in dlnorm (PR#1781)
The density of a lognormal should be 0 for negative arguments, but
> dlnorm(-1)
[1] NaN
Warning message:
NaNs produced in: dlnorm(x, meanlog, sdlog, log)
A simple fix is to change dlnorm's definition to:
function (x, meanlog = 0, sdlog = 1, log = FALSE)
.Internal(dlnorm(x*(x>0), meanlog, sdlog, log))
It might be faster to put the same sort of adjustment into the
internal code, but
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
2005 Jun 29
2
MLE with optim
Hello,
I tried to fit a lognormal distribution by using optim. But sadly the output
seems to be incorrect.
Who can tell me where the "bug" is?
test = rlnorm(100,5,3)
logL = function(parm, x,...) -sum(log(dlnorm(x,parm,...)))
start = list(meanlog=5, sdlog=3)
optim(start,logL,x=test)$par
Carsten.
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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
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
2009 Feb 11
3
Generating Numbers With Certain Distribution in R
Dear all,
Is there a way to generate K numbers of integer (K = 10^6).
The maximum value of the integer is 200,000 and minimum is 1.
And the occurrences of this integer follows
a lognormal distribution.
- Gundala Viswanath
Jakarta - Indonesia
2010 Jul 13
1
Batch file export
Dear all,
I have a code that generates data vectors within R. For example assume:
z <- rlnorm(1000, meanlog = 0, sdlog = 1)
Every time a vector has been generated I would like to export it into a csv
file. So my idea is something as follows:
for (i in 1:100) {
z <- rlnorm(1000, meanlog = 0, sdlog = 1)
write.csv(z, "c:/z_i.csv")
Where "z_i.csv" is a filename that is
2009 Aug 07
0
Fitting Truncated Distribution
Dear All,
I know that this topic has been already discussed on this list (see e.g.
http://markmail.org/message/bq2bdxwblwl4rpgf?q=r+fit+truncated+lognormal&page=1&refer=2ufc4fb2eftfwwml#query:r%20fit%20truncated%20lognormal+page:1+mid:7wxgkdxhixotorr5+state:results
for the case of weibull distribution), but I am experiencing some problems.
I deal with truncated distributions (that this to
2011 Jan 02
1
How to compute the density of a variable that follows a proportional error distribution
Hello,
I am trying to compute the density of a variable k that is either (1)
Normally distributed; (2) Log-Normally distributed; or (3) follows
proportional error distribution. I tried to search R-help and the answer for
normal distribution was easy to find (please see 1c). I am not sure if my
formula for dlnorm is correct (please see 2c below)? I really don't know
what function to use for the
2003 Aug 05
1
error message in fitdistr
Hi R lovers
Here is a numerical vector test
> test
[1] 206 53 124 112 92 77 118 75 48 176 90 74 107 126 99 84 114
147 99 114 99 84 99 99 99 99 99 104 1 159 100 53
[33] 132 82 85 106 136 99 110 82 99 99 89 107 99 68 130 99 99
110 99 95 153 93 136 51 103 95 99 72 99 50 110 37
[65] 102 104 92 90 94 99 76 81 109 91 98 96 104 104 93 99 125
89
2012 Jun 03
0
Bug in truncgof package?
Dear Carlos, Duncan and everyone
You may have already sorted the matter by now, but since I have not seen
anything posted since Duncan's reply, here I go. I apologize in advance
for the spam, if it turns out I've missed some post.
I think the test and the implementation of the truncgof package are just
fine. I've done Carlos' experiment (repeatedly generating samples and
testing
2009 May 31
1
Bug in truncgof package?
Dear R-helpers,
I was testing the truncgof CRAN package, found something that looked
like a bug, and did my job: contacted the maintainer. But he did not
reply, so I am resending my query here.
I installed package truncgof and run the example for function ad.test. I
got the following output:
set.seed(123)
treshold <- 10
xc <- rlnorm(100, 2, 2) # complete sample
xt <- xc[xc >=