Displaying 20 results from an estimated 121 matches for "rlnorm".
2005 Jan 07
3
lognorm
Hi!
I 've a problem to have a lognorm distribution with
mean=1 and var (or sigma)=1.
rlnorm(1000,0,0)
rlnorm(1000,1,1)
rlnorm(1000,0,1)
.... ?
Can you help me?
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...
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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2012 Sep 01
2
help on setting boundaries for generating random numbers
Dear All,
is there a way to set low and high limits to a simulation with rlnorm()?
as an example:
a <-rlnorm(500,0.7,1)
I get the summary of
Min. 1st Qu. Median Mean 3rd Qu. Max.
0.1175 1.0590 2.1270 3.4870 4.0260 45.3800
I would like to set limits so that the simulated values minimum would be greater then 0.5 and maximum of less than 30. If durin...
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
2010 Jun 21
2
How to predict the mean and variance of the dependent variable after regression
Hi, folks,
As seen in the following codes:
x1=rlnorm(10)
x2=rlnorm(10,mean=2)
y=rlnorm(10,mean=10)### Fake dataset
linmod=lm(log(y)~log(x1)+log(x2))
After the regression, I would like to know the mean of y. Since log(y) is
normal and y is lognormal, I need to know the mean and variance of log(y)
first. I tried mean (y) and mean(linmod), but either...
2009 May 20
1
sem with categorical data
...cmaster.ca/jfox/Misc/sem/SEM-paper.pdf.
When I apply the hetcor function, I receive the following error:
Error in checkmvArgs(lower = lower, upper = upper, mean = mean, corr = corr,
:
at least one element of 'lower' is larger than 'upper'
Example:
set.seed(781)
q1 <- cut2(x = rlnorm(n = 1e2, m = 2), cuts = seq(1,6))
q2 <- cut2(x = rlnorm(n = 1e2, m = 0), cuts = seq(1,6))
q3 <- cut2(x = rlnorm(n = 1e2, m = 1), cuts = seq(1,6))
dat <- data.frame(q1,q2,q3)
hetcor(data = dat, ML = T, pd = T, use = 'p')
Any help in understanding and correcting the error would be a...
2008 Feb 20
3
reshaping data frame
...I tried with
reshape{stats} and melt{reshape} but I was missing something. Any help is
very welcome. Please find details below:
#################################
# data in its original shape:
indiv <- rep(c("A","B"),c(10,10))
level.1 <- rpois(20, lambda=3)
covar.1 <- rlnorm(20, 3, 1)
level.2 <- rpois(20, lambda=3)
covar.2 <- rlnorm(20, 3, 1)
my.dat <- data.frame(indiv,level.1,covar.1,level.2,covar.2)
# the values of level.1 and level.2 represent the number of cases for the
particular
# combination of indiv*level*covar value
# I would like to do two things:...
2012 Oct 14
0
multivariate lognormal distribution simulation in compositions
Dear All,
thanks to Berend, my question posted yesturday was solved succesfully here: http://r.789695.n4.nabble.com/hep-on-arithmetic-covariance-conversion-to-log-covariance-td4646068.html . I posted the question with the assumption of using the results with rlnorm.rplus() from compositions. Unfortunatelly, I am not getting reasonable enough outcome. Am I applying the results wrongfully? The example: I have known means and cov matrix of a multivariate distribution as follows:
sigma <-matrix(c(0.0037,-0.0001,-0.0370,-0.0136,0.0026,-0.0001,0.0001,0.0008,-0...
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)$par
Carsten.
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2009 Feb 11
3
Generating Numbers With Certain Distribution in R
Dear all,
Is there a way to generate K numbers of integer (K = 10^6).
The maximum value of the integer is 200,000 and minimum is 1.
And the occurrences of this integer follows
a lognormal distribution.
- Gundala Viswanath
Jakarta - Indonesia
2012 Oct 11
2
Help on probability distribution question
...th a normal distribution but in the "log-domain" to avoid from negative values to be generated. Since the expected mean and SD is usually known from the normal domain, using the methods described in the wikipedia article "Arithmetric moments" I generate μand σ and simulate with rlnorm(). At times though the following issue comes up: I have the mean and SD for the parameters available from the normal domain, and the covariance matrix from the normal domain. Then I would like to simulate the values, but to avoid from negative values being generated I have to fall back on rlnorm in...
2009 Jul 20
3
Histograms on a log scale
...http://tolstoy.newcastle.edu.au/R/help/05/09/12044.html
https://stat.ethz.ch/pipermail/r-help/2002-June/022295.html
http://www.harding.edu/fmccown/R/#histograms
Now, consider the code snippet taken from
http://www.harding.edu/fmccown/R/#histograms
# Get a random log-normal distribution
r <- rlnorm(1000)
# Get the distribution without plotting it using tighter breaks
h <- hist(r, plot=F, breaks=c(seq(0,max(r)+1, .1)))
# Plot the distribution using log scale on both axes, and use
# blue points
plot(h$counts, log="xy", pch=20, col="blue",
main="Log-normal distr...
2012 May 16
3
finding mean and SD for a log-normal distribution
...d best describe it when resimulated using log normal distribution. Currently I am using another software to estimate the respective mean and SD on the log scale and the results are: 1.6667 and SD 0.47071. Then, to best reproduce my original distribution in R, I use the following commands:
c <- rlnorm(5000,1.6667,0.47071)
d <- exp(c)
mean(c)
sd(c)
and the results for mean and SD are 5.92 and 2.94 (original 6 and 3), respectively, which I am reasonably happy with. I would like to grow independent of the another software I use, but am unable to figure out how to generate the values of 1.6667...
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...
2012 Apr 20
1
Ternaryplot as an inset graph
...this particular
function. It overlays the old plot rather than plotting as an inset.
Here is a simple version of what I'm trying. Note that if I change the
inset plot to be an ordinary scatter, for instance, it works as
expected.
library(ade4)
library(vcd)
tdat <- data.frame(x=runif(20), y=rlnorm(20), z=rlnorm(20))
insetPlot <- function(data){
ternaryplot(data)
}
ternaryplot(tdat)
add.scatter(insetPlot(tdat), posi="topleft", ratio=.2)
Thanks very much,
Jennifer Young
Fisheries and Oceans Canada
Jennifer.Young@dfo-mpo.gc.ca
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2009 May 31
1
Bug in truncgof package?
...ncgof 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 >= treshold] # left truncated sample
ad.test(xt, "plnorm", list(meanlog = 2, sdlog = 2), H = 10)
Supremum Class Anderson-Darling Test
data: xt
AD = 3.124, p-value = 0.12
alternative hypothesis: two.sided
treshold = 10, simulatio...
2013 Mar 18
2
Fit a mixture of lognormal and normal distributions
Hello
I am trying to find an automated way of fitting a mixture of normal and log-normal distributions to data which is clearly bimodal.
Here's a simulated example:
x.1<-rnorm(6000, 2.4, 0.6)x.2<-rlnorm(10000, 1.3,0.1)X<-c(x.1, x.2)
hist(X,100,freq=FALSE, ylim=c(0,1.5))lines(density(x.1), lty=2, lwd=2)lines(density(x.2), lty=2, lwd=2)lines(density(X), lty=4)
Currently i am using mixtools and just run:
library(mixtools)mixmdl = normalmixEM(X, k=2, epsilon = 1e-08, maxit = 1000, maxrestarts=20,...
2012 Oct 30
6
standard error for quantile
Dear all
I have a question about quantiles standard error, partly practical
partly theoretical. I know that
x<-rlnorm(100000, log(200), log(2))
quantile(x, c(.10,.5,.99))
computes quantiles but I would like to know if there is any function to
find standard error (or any dispersion measure) of these estimated
values.
And here is a theoretical one. I feel that when I compute median from
given set of values it will...
2008 Feb 02
2
Confidence Interval
I have a model as follows:
x <- replicate(100, sum(rlnorm(rpois(1,5), 0,1)))
y <- quantile(x, 0.99))
How would one go about estimating the boundaries of a 95% confidence
interval for y?
Any pointers would be greatly appreciated.
> version
_
platform i386-pc-mingw32
arch i386
os mingw32
system i386, mingw32
status
major 2
minor 5.1
year 2007
month...