Displaying 20 results from an estimated 700 matches similar to: "Fitting a Weibull/NaNs"
2002 Oct 21
2
More Logistic Regression Tools?
I've been using R to do logistic regresssion, and that's working
well, but there are two things I haven't figured out how to do.
(1) Is there some pre-existing function that will let you compute the
odds ratios and confidence intervals for them for a specific fit. I know
how to do this manually or even write a function that I can call with
the coefficients and se, but
2012 Feb 21
5
help error: In dweibull(x, shape, scale, log) : NaNs produzidos
Guys,
I'm having an error when I use the command:
library(MASS)> dados<-read.table("inverno.txt",header=FALSE)> vento50<-fitdistr(dados[[1]],densfun="weibull")Mensagens de aviso perdidas:1: In dweibull(x, shape, scale, log) : NaNs produzidos2: In dweibull(x, shape, scale, log) : NaNs produzidos3: In dweibull(x, shape, scale, log) : NaNs produzidos4: In
2002 Oct 24
2
glm and lrm disagree with zero table cells
I've noticed that glm and lrm give extremely different results if you
attempt to fit a saturated model to a dataset with zero cells. Consider,
for instance the data from, Agresti's Death Penalty example [0].
The crosstab table is:
, , PENALTY = NO
VIC
DEF BLACK WHITE
BLACK 97 52
WHITE 9 132
, , PENALTY = YES
VIC
DEF BLACK WHITE
BLACK 6 11
2003 Jun 23
0
Reliability analysis and Laplace factor functions
Is there some package out there that implements functions
for reliability analysis, especially for software reliability?
In particular, I'm looking for:
* Laplace factor (Cox & Lewis 1978)
* Goel-Okumoto fitting
Thanks in advance,
-Ekr
--
[Eric Rescorla ekr at rtfm.com]
2006 Jul 14
1
dweibull retuns NaN instead of Inf (PR#9080)
Full_Name: G?ran Brostr?m
Version: 2.3.1
OS: Linux, ubuntu
Submission from: (NULL) (85.11.40.53)
> dweibull(0, 0.5, 1)
[1] NaN
Warning message:
NaNs produced in: dweibull(x, shape, scale, log)
should give Inf (and no Warning). Compare with
> dgamma(0, 0.5, 1)
[1] Inf
This happens when 'shape' < 1.
2005 Jul 22
1
multiplicate 2 functions
Thks for your answer,
here is an exemple of what i do with the errors in french...
> tmp
[1] 200 150 245 125 134 345 320 450 678
> beta18
Erreur : Objet "beta18" not found //NORMAL just to show it
> eta
[1] 500
> func1<-function(beta18) dweibull(tmp[1],beta18,eta)
> func1<-func1(beta18) * function(beta18)
dweibull(tmp[2],beta18,eta)
Erreur dans dweibull(tmp[1],
2006 Apr 06
0
More Logistic Regression Tools?
Frank E Harrell Jr wrote:
> Eric Rescorla <ekr at rtfm.com> wrote:
>
>> (2) I'd like to compute goodness-of-fit statistics for my fit
>> (Hosmer-Lemeshow, Pearson, etc.). I didn't see a package that
>> did this. Have I missed one?
>
> Hosmer-Lemeshow has low power and relies on arbitrary binning of
> predicted probabilities. The Hosmer-Le Cessie
2000 Jan 27
1
error in dweibull (PR#405)
Full_Name: R. Woodrow Setzer, Jr.
Version: 0.90.1
OS: linux - Redhat 6.1
Submission from: (NULL) (165.247.155.206)
dweibull(0,1,1) evaluates to 0; it should be 1.
Note that dweibull(.Machine$double.eps) evaluates to 1.
> dweibull(.01,1,1)
[1] 0.9900498
> dweibull(.00001,1,1)
[1] 0.99999
> dweibull(.Machine$double.eps,1,1)
[1] 1
> dweibull(0,1,1)
[1] 0
2011 Apr 27
3
MASS fitdistr with plyr or data.table?
I am trying to extract the shape and scale parameters of a wind speed
distribution for different sites. I can do this in a clunky way, but
I was hoping to find a way using data.table or plyr. However, when I
try I am met with the following:
set.seed(144)
weib.dist<-rweibull(10000,shape=3,scale=8)
weib.test<-data.table(cbind(1:10,weib.dist))
2012 Feb 21
3
HELP ERROR Weibull values must be > 0
GUYS,
I NEED HELP WITH ERROR:
library(MASS)
> dados<-read.table("mediaRGinverno.txt",header=FALSE)
> vento50<-fitdistr(dados[[1]],densfun="weibull")
Erro em fitdistr(dados[[1]], densfun = "weibull") :
Weibull values must be > 0
WHY RETURN THIS ERROR? WHAT CAN I DO?
BEST REGARDS
[[alternative HTML version deleted]]
2006 Jun 02
2
Problem with mle
R 2.3.0
Linux, SuSE 10.0
Hi
I have two problems with mle - probably I am using it the wrong way so
please let me know.
I want to fit different distributions to an observed count of seeds and
in the next step use AIC or BIC to identify the best distribution.
But when I run the script below (which is part of my original script), I
get one error message for the first call of mle:
Error in
2011 Oct 20
1
R code Error : Hybrid Censored Weibull Distribution
Dear Sir/madam,
I'm getting a problem with a R-code which calculate Fisher Information
Matrix for Hybrid Censored Weibull Distribution. My problem is that:
when I take weibull(scale=1,shape=2) { i.e shape>1} I got my desired
result but when I take weibull(scale=1,shape=0.5) { i.e shape<1} it gives
error : Error in integrate(int2, lower = 0, upper = t) : the integral is
probably
2009 Apr 30
1
finite mixture model (2-component Weibull): plotting Weibull components?
Dear Knowledgeable R Community Members,
Please excuse my ignorance, I apologize in advance if this is an easy question, but I am a bit stumped and could use a little guidance.
I have a finite mixture modeling problem -- for example, a 2-component Weibull mixture -- where the components have a large overlap, and
I am trying to adapt the "mclust" package which concern to normal
2005 Jul 22
1
Generate a function
hi all,
I need to generate a function inside a loop:
tmp is an array
for (i in 1:10)
{
func<- func * function(beta1) dweibull(tmp[i],beta1,eta)
}
because then i need to integrate this function on beta.
I could have written this :
func<-function(beta1) prod(dweibull(tmp,beta1,eta)) (with eta and beta1 set)
but it is unplottable and no integrable... i could make it a bit different but
2008 Oct 29
0
Error using fitting weibull distribution to some data
Dear R-users,
Using Maximum-likelihood Fitting (fitdistr function) I've got the next
error:
> fitdistr(datos,"weibull",lower=0)
Error in optim(x = c(1.4625e-06, 0.257854, 0.0001217545, 0.11421005,
0.028721576, :
L-BFGS-B *needs finite values of 'fn' *
where "datos" is a vector of length=1000 between 1.4625e-06 and 0.8867114
I add the lower argument in
2009 Nov 20
2
How to use results of distribution fitting for further processing?
This is probably simple, but I have a hard time finding the solution. Any help greatly appreciated.
I would like to use the results of fitdistr(z,densfun=dweibull,start=list(scale=1,shape=1)) for further processing. How do I assign the values of scale and shape to b and a without manually entering the numbers?
TIA
__________________________________________________________________
2008 Apr 15
1
Weibull
Dear R users,
This is a basic question.
I want to fit a Weibull distribution. fitdistr(data, "weibull") works and it
is a maximum likelihood fitting. Is it a good method ? Or is it better to
write a function for the log-likelihood and the gradient and to use a
numerical routine ?
Fitdistr works for uncensored data, but what can I use for censored (and
uncensored) data ?
Thank you
2001 Aug 28
2
Estimating Weibull Distribution Parameters - very basic question
Hello,
is there a quick way of estimating Weibull parameters for some data points
that are assumed to be Weibull-distributed?
I guess I'm just too lazy to set up a Maximum-Likelihood estimation...
...but maybe there is a simpler way?
Thanks for any hint (and yes, I've read help(Weibull) ;)
Kaspar Pflugshaupt
--
Kaspar Pflugshaupt
Geobotanical Institute
ETH Zurich, Switzerland
2012 Feb 23
3
why is generating the same graph???
Hi,
why my script iss always generating the same graph?when I change the parameters and the name of text file?
library(MASS)
dados<-read.table("inverno.txt",header=FALSE)
vento50<-fitdistr(dados[[1]],densfun="weibull")
png(filename="invernoRG.png",width=800,height=600)
hist(dados[[1]], seq(0, 18, 0.5), prob=TRUE, xlab="Velocidade
2011 Nov 03
1
Fit continuous distribution to truncated empirical values
Hi all,
I am trying to fit a distribution to some data about survival times.
I am interested only in a specific interval, e.g., while the data lies in the interval (0,...., 600), I want the best for the interval (0,..., 24).
I have tried both fitdistr (MASS package) and fitdist (from the fitdistrplus package), but I could not get them working, e.g.
fitdistr(left, "weibull", upper=24)