Displaying 20 results from an estimated 10000 matches similar to: "Browser to replace the internal browser?"
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
[[alternative HTML version deleted]]
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 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.
[[alternative HTML version deleted]]
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 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 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 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
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
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
2005 Sep 07
1
fitting distribution tails
Hello,
I want to fit a distribution to a dataset. Important is not the "overall"
fitting but the fitting in the tail (e.g. all observations > x or the n
highest values). Standard ML-estimation sometimes doesn't work here very
well. We see that especially when we have truncated datasets the algorithms
won't converge. In the case of lognormal distribution: It seems that the
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
[[alternative HTML version deleted]]
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
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:
2006 Jun 11
1
MS-Access and R
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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
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
2005 Jun 19
1
practical help ... solving a system...
Hello,
I want to estimate the parameters of a binomial distributed rv using MLE.
Other distributions will follow.
The equation system to solve is not very complex, but I've never done such
work in R and don't have any idea how to start...
The system is:
(1) n*P = X
(2) [sum {from j=0 to J-1} Y{j} /(n-j)] = -n * ln (1-X / n)
where * only X is given (empirical mean)
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
2006 Jun 18
1
Bayesian Networks with deal
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2006 Jul 26
1
arima() function - issues
Hi,
My query is related to ARIMA function in stats package.
While looking for the time series literature I found following link which
highlights discrepancy in "arima" function while dealing with
differenced time series. Is there a substitute function similar to
"sarima" mentioned in the following website implemened in R? Any pointers would
be of great help.