Displaying 20 results from an estimated 1100 matches similar to: "fitting distributions using fitdistr (MASS)"
2013 Jan 22
2
Assistant
Good-day Sir,
I am R.Language users but am try to? estimate parameter of beta distribution particular dataset but give this error, which is not clear to me: (Initial value in "vmmin" is not finite)
beta.fit <- fitdistr(data,densfun=dbeta,shape1=value , shape2=value)
kindly assist.
expecting your reply:
2003 Jul 04
1
Problem with fitdistr for beta
I have the following problem:
I have a vector x of data (0<x<=1 ) with
a U-shaped histogram and try to fit a beta
distribution using fitdistr. In fact,
hist(rbeta(100,0.1,0.1)) looks a lot like
my data.
The equivalent to
the example in the manual
sometimes work:
> a <- rbeta(100,0.1,0.1)
> fitdistr(x=a, "beta", start=list(shape1=0.1,shape2=0.1))1)
> shape1
2011 Aug 01
3
Beta fit returns NaNs
Hi,
sorry for repeating the question but this is kind of important to me and i
don't know whom should i ask.
So as noted before when I do a parameter fit to the beta distr i get:
fitdist(vectNorm,"beta");
Fitting of the distribution ' beta ' by maximum likelihood
Parameters:
estimate Std. Error
shape1 2.148779 0.1458042
shape2 810.067515 61.8608126
Warning
2005 Nov 17
1
Fitdistr()
When using fitdistr() with the exponential, log-normal and beta distributions,
you get the relevent rate, mean, standard deviation, shape1 and shape2 but
you get a number bellow those that are in () and I was wandering what exactly
those numbers represent and how they relate to the data.
Many thanks
Mark Miller
2008 Aug 03
2
Determining model parameters
This may be a begining question. If so, please bear with me.
If I have some data that based on the historgram and other plots it "looks" like a beta distribution. Is there a function or functions within R to help me determine the model parameters for such a distirbution? Similarily for other "common" distirbutions, Poisson(lambda), Chi-Square(degrees of freedom, chi-square
2011 Oct 01
1
Fitting 3 beta distributions
Hi,
I want to fit 3 beta distributions to my data which ranges between 0 and 1.
What are the functions that I can easily call and specify that 3 beta
distributions should be fitted?
I have already looked at normalmixEM and fitdistr but they dont seem to be
applicable (normalmixEM is only for fitting normal dist and fitdistr will
only fit 1 distribution, not 3). Is that right?
Also, my data has 26
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
2017 Dec 21
1
Fitting Beta Distribution
Dear All,
I need to fit a custom probability density (based on the symmetric beta
distribution B(shape, shape), where the two parameters shape1 and shape2
are identical) to my data.
The trouble is that I experience some problems also when dealing with the
plain vanilla symmetric beta distribution.
Please consider the code at the end of the email.
In the code, dbeta1 is the density of the beta
2017 Dec 21
0
Fitting Beta Distribution
I answer my own question: I had overlooked the fact that the normalization
factor is also a function of the parameters I want to optimise, hence I
should write
dbeta2 <- function(x, shape){
res <- x^(shape-1)*(1-x)^(shape-1)/beta(shape, shape)
return(res)
}
after which the results are consistent.
---------- Forwarded message ----------
From: Lorenzo Isella <lorenzo.isella
2012 Mar 15
2
Integrate inside function
Dear R users,
first I take this opportunity to greet all the R community for your
continuous efforts.
I wrote a function to calculate the pdf and cdf of a custom distribution
(mixed gamma model).
The function is the following:
pmixedgamma3 <- function(y, shape1, rate1, shape2, rate2, prev)
{
density.function<-function(x)
{
shape1=shape1
rate1=rate1
shape2=shape2
2018 Jul 12
2
Problemas con la funcion "apply"
Buenos dias!
Os escribo para ver si me podeis ayudar con un asunto en el que me he quedado un poco encallado.
Lo que tengo que hacer es sacar los percentiles (0.001, 0.005, 0.95 y 0.999) de varias distribuciones beta, concretamente 418. Cada distribucion esta definida por los parametros "shape1" y "shape2". Por lo tanto tengo una base de datos de 418 filas y en cada una de
2012 Aug 27
3
How to generate a matrix of Beta or Binomial distribution
Hi folks,
I have a question about how to efficiently produce random numbers from Beta
and Binomial distributions.
For Beta distribution, suppose we have two shape vectors shape1 and shape2.
I hope to generate a 10000 x 2 matrix X whose i th rwo is a sample from
reta(2,shape1[i]mshape2[i]). Of course this can be done via loops:
for(i in 1:10000)
{
X[i,]=rbeta(2,shape1[i],shape2[i])
}
However,
2020 Mar 26
4
unstable corner of parameter space for qbeta?
I've discovered an infelicity (I guess) in qbeta(): it's not a bug,
since there's a clear warning about lack of convergence of the numerical
algorithm ("full precision may not have been achieved"). I can work
around this, but I'm curious why it happens and whether there's a better
workaround -- it doesn't seem to be in a particularly extreme corner of
parameter
2007 Nov 13
1
TRUNCATED error with data frame
Hi ,
I am new to R.
I am trying to run a simple R script as shown below:
aov.R
------
data1<-c(49,47,46,47,48,47,41,46,43,47,46,45,48,46,47,45,49,44,44,45,42,45,45,40
,49,46,47,45,49,45,41,43,44,46,45,40,45,43,44,45,48,46,40,45,40,45,47,40)
matrix(data1, ncol= 4, dimnames = list(paste("subj", 1:12),
c("Shape1.Color1",
"Shape2.Color1", "Shape1.Color2",
2011 Jul 29
1
How to interpret Kolmogorov-Smirnov stats
Hi,
Interpretation problem ! so what i did is by using the:
>fit1 <- fitdist(vectNorm,"beta")
Warning messages:
1: In dbeta(x, shape1, shape2, log) : NaNs produced
2: In dbeta(x, shape1, shape2, log) : NaNs produced
3: In dbeta(x, shape1, shape2, log) : NaNs produced
4: In dbeta(x, shape1, shape2, log) : NaNs produced
5: In dbeta(x, shape1, shape2, log) : NaNs produced
6: In
2009 Jul 01
1
Plot cumulative probability of beta-prime distribution
Hallo,
I need your help.
I fitted my distribution of data with beta-prime, I need now to plot the
Cumulative distribution. For other distribution like Gamma is easy:
x <- seq (0, 100, 0.5)
plot(x,pgamma(x, shape, scale), type= "l", col="red")
but what about beta-prime? In R it exists only pbeta which is intended only
for the beta distribution (not beta-prime)
This is
2013 May 14
2
invalid operands of types ‘SEXPREC*’ and ‘R_len_t’ to binary ‘operator/’ with Rcpp.
Dear R-Developers,
I just started learning how to use Rcpp. Earlier while using it, I
encountered an error as shown below:
file74d8254b96d4.cpp: In function ‘Rcpp::NumericVector
foo(Rcpp::NumericVector, Rcpp::NumericVector, Rcpp::NumericVector,
Rcpp::Function, Rcpp::Function)’:
file74d8254b96d4.cpp:10: error: invalid operands of types ‘SEXPREC*’ and
‘R_len_t’ to binary ‘operator/’
make: ***
2006 Jul 04
1
problem getting R 2.3.1 svn r38481 to pass make check-all
Hi,
I noticed this problem on my home desktop running FC4 and again on my
laptop running FC5. Both have previously compiled and passed make
check-all on 2.3.1 svn revisions from 10 days ago or so. On both these
machines, make check-all is consistently failing (4 out of 4 attempts on
the FC 4 desktop and 3 out of 3 on the FC 5 laptop) in the
p-r-random-tests tests. This is with both default
2011 Apr 07
2
Two functions as parametrs of a function.
Hi R users:
I'm trying to make a function where two of the parameters are
functions, but I don't know how to put each set of parameters for
each function.
What am I missing?
I try this code:
f2<-function(n=2,nsim=100,fun1=rnorm,par1=list(),fun2=rnorm,par2=list()){
force(fun1)
force(fun2)
force(n)
p1<-unlist(par1)
p2<-unlist(par2)
force(p1)
force(p2)
2020 Mar 26
0
unstable corner of parameter space for qbeta?
>>>>> Ben Bolker
>>>>> on Wed, 25 Mar 2020 21:09:16 -0400 writes:
> I've discovered an infelicity (I guess) in qbeta(): it's not a bug,
> since there's a clear warning about lack of convergence of the numerical
> algorithm ("full precision may not have been achieved"). I can work
> around this, but I'm