Displaying 20 results from an estimated 5000 matches similar to: "fitting distribution tails"
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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2005 Jan 31
2
ML-Fit for truncated distributions
Hello,
maybe that my Question is a "beginner"-Question, but up to now, my research
didn't bring any useful result.
I'm trying to fit a distribution (e.g. lognormal) to a given set of data
(ML-Estimation). I KNOW about my data that there is a truncation for all
data below a well known threshold. Is there an R-solution for an
ML-estimation for this kind of data-problem? As
2013 Jan 06
4
random effects model
Hi A.K
Regarding my question on comparing normal/ obese/overweight with blood
pressure change, I did finally as per the first suggestion of stacking the
data and creating a normal category . This only gives me a obese not obese
14, but when I did with the wide format hoping to get a
obese14,normal14,overweight 14 Vs hibp 21, i could not complete any of the
models.
This time I classified obese=1
2005 Jul 12
1
three par. fitting with fitdistr
Hello,
I want to fit a tree parameter distribution to given data. I tried it with
sample data using the "fitdistr" function.
Here my workflow that didn't had any result:
I started with the generalized gamma distr, which is:
r*dgamma(x^r,shape,rate)
The R-function is:
ggamma = function (x,r,shape,rate) r*dgamma(x^r,shape,rate=rate)
For the first step I assumed r = 1 and I
2005 Jun 09
4
position of a legend-object
Hello,
I've written a function that plots a few functions in a diagram.
The xlim and or ylim is not always the same, and set automatically by R.
A legend is part of this object.
Now the problem is: where to put the legend? Me would help a function that
returns the limits and scaling of the axis.
Thanks for your help.
Carsten
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2005 Feb 02
2
Frequency of Data
Hello,
just another problem in R, maybe it's simple to solve for you. I didn't find
a solution up to now, but I'm convinced that I'm not the only one who
has/had a similar problem. Maybe there's a ready-made function in R?
The prob:
I've imported a CSV-file into R with 1000 dates of an observed event
(there's only information of the date. When there happend no
2005 Feb 25
2
Simulation Progress
Hi,
I've made a function that executes a monte-carlo simulation.
It always needs a lot of time until e.g. 1Mio simulation steps are done.
So I would like to know, how many percent of the work is already done.
In an Excel/VBA Solution I could easily implement a status bar or status
window.
How could an R-Solution look like?
Carsten
2005 Mar 12
1
MLE for two random variables
Hello,
I've the following setting:
(1) Data from a source without truncation (x)
(2) Data from an other source with left-truncation at threshold u (xu)
I have to fit a model on these these two sources, thereby I assume that both
are "drawn" from the same distribution (eg lognormal). In a MLE I would sum
the densities and maximize. The R-Function could be:
2005 Jul 19
2
Problems with date-format (R 2.1.1 + chron)
Hello,
today I've updated on the newest R-Version. But sadly a function I needed
didnt want to work:
The input is e.g.
days(as.Date("21-07-2005","%d-%m-%y"))
the error is: Fehler in Math.Date(dts): floor nicht definiert f??r Date
Objekte
(Error in Math.Date(dts): floor not defined for date objects)
Same for year. Only months gives me the correct output.
In Version
2005 Mar 23
2
Browser to replace the internal browser?
Hello,
I see that the more I work with R and the more the code gets larger I would
like to have some graphic support in my quellcode.
Is there a browser that could be easily implemened in R?
And how do I call it from R? It would be nice if the browser replaces the
"fix()" function.
Carsten
2012 Dec 28
3
help with reshaping wide to long format
Hi, Sorry, but how did you bring it out?
Thanks
On Fri, Dec 28, 2012 at 8:48 AM, arun kirshna [via R] <
ml-node+s789695n4654093h10@n4.nabble.com> wrote:
> Hi,
> bp.sub<- structure(list(CODEA = c(1L, 3L, 4L, 7L, 8L, 9L, 10L, 11L, 12L,
> 13L, 14L, 16L, 17L), C45 = c(NA, 2L, 2L, 2L, 2L, 1L, NA, 1L,
> 1L, 2L, 1L, 2L, 1L), ragek = c(3L, 3L, 3L, 4L, 4L, 3L, 3L, 3L,
> 3L, 3L,
2005 Apr 05
1
Fitdistr and likelihood
Hi all,
I'm using the function "fitdistr" (library MASS) to fit a distribution to
given data.
What I have to do further, is getting the log-Likelihood-Value from this
estimation.
Is there any simple possibility to realize it?
Regards, Carsten
2006 Mar 26
1
generating random events (dd-mm-yyyy)
Hello,
I have to generate a couple of random datasets to validate an actuarial
software.
Each set has to contain at least two columns: (1) Date of the loss events
occurrence; (2) Severity of loss
I'm generating the dates on a monthly basis by, for example:
ts(matrix(rpois(36,10)), start=c(2003, 1), frequency=12).
>From that output I generate dates "by hand", what is REALLY time
2006 Jun 11
1
MS-Access and R
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2006 Feb 08
1
Simple optim - question
Hello,
I want to find the parameters mu and sigma that minimize the following
function.
It's important, that mu and sigma are strictly positive.
-----------------
optimiere = function(fmean,smean,d,x,mu,sigma)
{
merk = c()
for (i in 1:length(d))
merk=c(merk,1/(d[i]^2)*(d[i]-1/(fmean*(1-plnorm(x[i],mu,sigma))))^2)
return(sum(merk))
}
-----------------
To do that I'm using the nlm
2015 Aug 02
3
ayuda con análisis de supervivencia
Hola a todos,
-Estoy estudiando el efecto de dos genotipos (~tratamientos) en la aparición de síndrome metabólico (MetS) con datos longitudinales recogidos a tiempo 0,7,10,15,20 y 25 años.
-He hecho un dataframe con las siguientes variables
MetS: Síndrome Metabólico (Si=1,No=0)
bmi: Indice de masa corporal (IMC) cuando se produce la conversión a MetS+ . Para los que permancen MetS-, esta variable
2005 Jun 23
2
solving equation system
Hello,
I want to solve some two dimensional equation system with R. Some systems
are not solvable analytically.
Here is an example:
(I) 1/n*sum{from_i=1_to_n}(Xi) = ln lambda + digamma(c)
(II) mean(X) = x / lambda
I want to find lambda and c,
which R-function could do that task?
Carsten
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2005 Feb 11
1
function table
Hi,
my problem is the following:
I have a large database of insurance-damage data and want to model the
frequency of these events. So to fit a distribution on my frequency-data I
want to count the number of events in each month via the date of occurrence.
Therefor I use this command which works very well:
count_table <- table(months(date_occ),years(date_occ))
But there is another
2007 Jan 26
1
Bayesian inference: Poisson distribution with normal (!) prior
Hello,
for a frequency modelling problem I want to combine expert knowledge with
incoming real-life data (which is not available up to now). The frequency
has to be modelled with a poisson distribution. The parameter lambda has to
be normal distributed (for certain reasons we did not NOT choose gamma
althoug it would make everything easier).
I've started with the subsequent two functions to
2005 Mar 21
1
working with tables
Hi,
two questions - I think simple to solve for you ...
(1) I've written a function containing some loops.
Each loop will generate a few outputs. Finally I have to combine them to get
something like a "spreadsheet" that my colleagues can import in EXCEL.
Up to now I'm doing it as follows:
With each loop-step I assign new values for each "column" of my desired
output