Displaying 20 results from an estimated 2000 matches similar to: "Error using fitting weibull distribution to some data"
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
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2008 Oct 07
3
Fitting weibull, exponential and lognormal distributions to left-truncated data.
Dear All,
I have two questions regarding distribution fitting.
I have several datasets, all left-truncated at x=1, that I am attempting
to fit distributions to (lognormal, weibull and exponential). I had
been using fitdistr in the MASS package as follows:
fitdistr<-(x,"weibull")
However, this does not take into consideration the truncation at x=1. I
read another posting in this
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
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
2011 Oct 28
1
weibull fitdistr problem: optimization failed
I'm getting errors when running what seems to be a simple Weibull
distribution function:
This works:
x <-
c(23,19,37,38,40,36,172,48,113,90,54,104,90,54,157,51,77,78,144,34,29,45,16,15,37,218,170,44,121)
rate <- c(.01,.02,.04,.05,.1,.2,.3,.4,.5,.8,.9)
year <- c(100,50,25,20,10,5,3.3,2.5,2,1.2,1.1)
library(MASS)
x <- sort(x)
tryCatch(
f<-fitdistr(x, 'weibull'),
error
2003 Oct 20
1
Fitting a Weibull/NaNs
I'm trying to fit a Weibull distribution to some data via maximum
likelihood estimation. I'm following the procedure described by Doug
Bates in his "Using Open Source Software to Teach Mathematical
Statistics" but I keep getting warnings about NaNs being converted to
maximum positive value:
> llfunc <- function (x) { -sum(dweibull(AM,shape=x[1],scale=x[2], log=TRUE))}
>
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)
2008 Oct 22
2
Weibull parameter estimation
Dear R-users
I would like to fit weibull parameters using "Method of moments" in order to
provide the inital values of the parameter to de function 'fitdistr' . I
don`t have much experience with maths and I don't know how to do it.
Can anyone please put me in the rigth direction?
Borja
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2003 Jul 28
1
Optimization failed in fitting mixture 3-parameter Weibull distri bution using fitdistr()
Dear All;
I tried to use fitdistr() in the MASS library to fit a mixture
distribution of the 3-parameter Weibull, but the optimization failed.
Looking at the source code, it seems to indicate the error occurs at
if (res$convergence > 0)
stop("optimization failed").
The procedures I tested are as following:
>w3den <- function(x, a,b,c)
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 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
2013 Oct 28
0
"Optimization fail" error from fitdistr (Weibull distribution)
Hello everyone,
This is Kangmin.
I am trying to produce shape and scale of my wind data. My data is based on
wind speed frequency with 1km/hr increment. data is described below.
Windspeed (km/h) Frequency
1 351
2 147
3 317
4 378
5 527
6 667
7 865
8 970
9 987
10 907
11 905
12 642
13 1000
14 983
15 847
16 842
17 757
18 698
19 632
20 626
21 599
22 529
23 325
24 391
2004 Sep 23
2
fitting weibull distribution
Dear all,
I get the following error message. And I cannot quite work out what is
wrong. I think the optim gets infinite values. Certainly my data do not
have any infinite values. How can I solve this?
fitdistr(A1, "weibull")
Error in optim(start, mylogfn, x = x, hessian = TRUE, ...) :
non-finite value supplied by optim
I am using R version 1.9.1 on RedHat Linux, Kernel 2.6.8.
2005 Sep 06
2
(no subject)
my problem actually arised with fitting the data to the weibulldistribution,
where it is hard to see, if the proposed parameterestimates make sense.
data1:2743;4678;21427;6194;10286;1505;12811;2161;6853;2625;14542;694;11491;
?? ?? ?? ?? ?? 14924;28640;17097;2136;5308;3477;91301;11488;3860;64114;14334
how am I supposed to know what starting values i have to take?
i get different
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
__________________________________________________________________
2006 Aug 16
3
fitting truncated normal distribution
Hello,
I am a new user of R and found the function dtnorm() in the package msm.
My problem now is, that it is not possible for me to get the mean and sd out of a sample when I want a left-truncated normal distribution starting at "0".
fitdistr(x,dtnorm, start=list(mean=0, sd=1))
returns the error message
"Fehler in "[<-"(`*tmp*`, x >= lower & x <= upper,
2008 Jun 28
1
How to estimate the parameters in a bivariate weibull distribution?
Hi,Dear all R experts,
As far as I know, fitdistr() is only to estimate the parameters in univariate distributions. I have a set of data (x,y) and I assume it follows a bivariate weibull distribution. Could someone tell me a function in R that is suitable for parameter estimation in multivariate cases? Thanks in advance!
Cheers,
YAN
2011 Jun 23
2
Confidence interval from resampling
Dear R gurus,
I have the following code, but I still not know how to estimate and extract
confidence intervals (95%CI) from resampling.
Thanks!
~Adriana
#data
penta<-c(770,729,640,486,450,410,400,340,306,283,278,260,253,242,240,229,201,198,190,186,180,170,168,151,150,148,147,125,117,110,107,104,85,83,80,74,70,66,54,46,45,43,40,38,10)
x<-log(penta+1)
plot(ecdf(x),
2010 Jan 12
1
Strange behavior when trying to piggyback off of "fitdistr"
Hello.
I am not certain even how to search the archives for this particular question, so if there is an obvious answer, please smack me with a large halibut and send me to the URLs.
I have been experimenting with fitting curves by using both maximum likelihood and maximum spacing estimation techniques. Originally, I have been writing distribution-specific functions in 'R' which work