Displaying 20 results from an estimated 9000 matches similar to: "fitting gaussian mixtures"
2017 Aug 24
1
Problem in optimization of Gaussian Mixture model
Hello,
I am facing a problem with optimization in R from 2-3 weeks.
I have some Gaussian mixtures parameters and I want to find the maximum in
that
*Parameters are in the form *
mean1 mean2 mean3 sigma1 sigma2 sigma3 c1 c2 c3
506.8644 672.8448 829.902 61.02859 9.149168 74.84682 0.1241933
0.6329082 0.2428986
I have used optima and optimx to find the
2011 Mar 14
0
Fitting 4 moments distribution w/ Mixture Gaussian
Hello,
I know that Mclust does the fitting on its own but I am trying to implement
an optimization with the aim to generate a the mixture gaussian with the
combine moments as closed as possible to the moment of my return
distribution.
The objective is to Min Abs((Mean Ret - MeanFit)/Mean Fit) + Abs((Std Ret
-Stdev Fit)/Stdev) + Abs((Sk Ret-Sk fit)/Sk Fit) + Abs((Kurt Ret- Kurt Fit))
Taking
2005 Sep 08
1
clustering: Multivariate t mixtures
Hi,
Before I write code to do it does anyone know of code for fitting
mixtures of multivariate-t distributions.
I can't use McLachan's EMMIX code because the license is "For non
commercial use only".
I checked, mclust and flexmix but both only do Gaussian.
Thanks
Nicholas
2017 Jun 29
0
package to fit mixtures of student-t distributions
Offlist, because this is (a) an opinion and (b) about statistics and
therefore offtopic.
I don't know whether any such package exists, but I would predict that
this is likely to be overdetermined (too many parameters) and
therefore unlikely to be a successful strategy. Fitting a mixture of
Gaussians is already difficult enough.
Feel free to ignore, of course, and no need to reply.
Cheers,
2017 Jun 29
1
package to fit mixtures of student-t distributions
I don?t see how neither a) or b) applies to this question nor the technical merit of the remark about mixture models.
Do you have a suggestion for a more appropriate forum for this issue/question? (stackoverflow basically sent me here).
Kind regards
> On 29. Jun 2017, at 16:58, Bert Gunter <bgunter.4567 at gmail.com> wrote:
>
> Offlist, because this is (a) an opinion and (b)
2017 Jun 29
0
package to fit mixtures of student-t distributions
Would package "teigen" help?
Ranjan
On Thu, 29 Jun 2017 14:41:34 +0200 vare vare via R-help <r-help at r-project.org> wrote:
> Hello!
>
> I am new to R (before used python exclusively and would actually call the R solution for this issue inside a python notebook, hope that doesn?t disqualify me right of the batch).
>
> Right now I am looking for a piece of
2010 Dec 26
0
Fitting mixtures with non-linear parameters constraints
Dear R users
Does anyone happen to know a function to fit a Gaussian mixture using
*non-linear* constraints?between the parameters? (An EM the allows
that will do the job obviously).
Thank you in advance
--
Jonathan Rosenblatt
www.john-ros.com
2017 Jun 29
6
package to fit mixtures of student-t distributions
Hello!
I am new to R (before used python exclusively and would actually call the R solution for this issue inside a python notebook, hope that doesn?t disqualify me right of the batch).
Right now I am looking for a piece of software to fit a 1D data sample to a mixture of t-distributions.
I searched quite a while already and it seems to be that this is a somehwat obscure endeavor as most
2017 Jul 02
0
package to fit mixtures of student-t distributions
Thanks Ranjan,
that provides exactly what I need.
I also got a more elaborate answer on stackoverflow (after the same question got rejected form cross validated?) with a running example for this package:
https://stackoverflow.com/questions/44825529/package-to-fit-mixtures-of-student-t-distributions/44827220#44827220
2005 Aug 17
1
Fitting mixture model
I would like to fit a gaussian mixture model to a vector with about 50,000
points. I have tried using Mclust to do so, but 50,000 points requires more
memory than I have (and I am running with 4Gb). Any other suggestions for
how to do so? Oh, I don't know the number of components, but the number
will likely be less than 5 or 6.
Thanks,
Sean
1999 Jun 08
1
inverse.gaussian, nbinom
Two questions:
1. inverse.gaussian is up there as one of the glm families, but do
people ever use it? There is no inverse.gaussian in the R
distribution family, and when I checked McCullagh & Nelder, it only
appeared twice in the book (according to subject index), once in the
table on p. 30 and once on p. 38 in a passing sentence. Is there a
good reference on this distribution?
2. When I
2017 Jun 30
0
package to fit mixtures of student-t distributions
gamlss.mx can fit these I believe (although no experience with these myself)
flexmix may be (relatively easily) adaptable to accomplish this as well
hth, Ingmar
Ingmar Visser
Universitair Hoofddocent ontwikkelingspsychologie | Directeur College
Psychologie
Afdeling Psychologie | Faculteit Maatschappij- en Gedragswetenschappen |
Universiteit van Amsterdam
Bezoek | Nieuwe Achtergracht 129B | Kamer
2004 Dec 17
1
package.skeleton()
Hi, R people:
I generated a package using package.skeleton(). But I can not load it using library().
> package.skeleton("RDIPcor", list = c("ROCAUC.i", "cor.i"), path = "/home/xiao")
Creating directories ...
Creating DESCRIPTION ...
Creating READMEs ...
Saving functions and data ...
Making help files ...
Done.
Further steps are described in
2012 Mar 19
1
fitting a histogram to a Gaussian curve
Hello,
I am trying to fit my histogram to a smooth Gaussian curve(the data
closely resembles one except a few bars).
This is my code :
#!/usr/bin/Rscript
out_file = "irc_20M_opencl_test.png"
png(out_file)
scan("my.csv") -> myvals
hist(myvals, breaks = 50, main = "My Distribution",xlab = "My Values")
pdens <- density(myvals, na.rm=T)
plot(pdens,
2006 Jul 04
1
Problems when computing the 1rst derivative of mixtures of densities
Hi everybody,
I am currently working on mixtures of two densities ( f(xi,teta)=
(1-teta)*f1(xi) + teta*f2(xi) ),
particularly on the behavior of the variance for teta=0 (so sample only
comes from the first distribution).
To determine the maximum likelihood estimator I use the Newton-Rapdon
Iteration. But when
computing the first derivative I get a none linear function (with several
asymptotes)
2003 Jul 17
3
univariate normal mixtures
Hello,
I have a concrete statistical question:
I have a sample of an univariate mixture of an unknown number (k) of
normal distributions, each time with an unknown mean `m_i' and a
standard deviation `k * m_i', where k is known factor constant for all
the normal distributions. (The `i' is a subscript.)
Is there a function in R that can estimate the number of normal
distributions k
2005 Oct 21
1
finite mixture model (2-component gaussian): plotting component gaussian 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 gaussian mixture -- where the components have a large overlap, and
I am trying to use the "mclust" package to solve this problem.
I need
2002 Dec 04
1
Mixture of Multivariate Gaussian Sample Data
Hey, I am confused about how to generate the sample data from a mixture of
Multivariate Gaussian ditribution.
For example, there are 2 component Gaussian with prior
probability of 0.4 and 0.6,
the means and variances are
u1=[1 1]', Cov1=[1 0;0 1]
and
u2=[-1 -1]', Cov2=[1 0;0 1]
repectively.
So how can I generate a sample of 500 data from the above mixture
distribution?
Thanks.
Fred
2008 Apr 03
1
How to ask for *fixed* number of distributions under parameterized Gaussian mixture model.
Dear R users:
I am wondering how to ask for *fixed* number of distributions under
parameterized Gaussian mixture model.
I know that em() and some related functions can predict the
parameterized Gaussian mixture model. However, there seems no
parameter to decide number of distributions to be mixed (if we known
the value in advance).
That is, assume I know the (mixed)data is from 3 different
2009 Aug 12
1
psi not functioning in nlrob?
Hi all,
I'm trying to fit a nonlinear regression by "nlrob":
model3=nlrob(y~a1*x^a2,data=transient,psi=psi.bisquare,
start=list(a1=0.02,a2=0.7),maxit=1000)
However an error message keeps popping up saying that the function
psi.bisquare doesn't exist.
I also tried psi.huber, which is supposed to be the default for nlrob:
model3=nlrob(y~a1*x^a2,data=transient,psi=psi.huber,