Displaying 20 results from an estimated 70000 matches similar to: "Scale mixture of normals"
2009 Jun 12
1
Mixture of normals
Can anyone send me the R code for fitting a mixture of normal distributions.
Or in fact any'combination' of mixtures of distributions. I looke dta mix
but it is still not clear to me.
Jim
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2005 Oct 11
0
random effects are mixture of normals
Dear All,
I wonder if there is an R package to estimate the generalized linear mixed models but with a random effects having a mixture of normals as a prior distributinon ..
Thank you,
Abderrahim
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2004 Nov 18
1
gibbs sampling for mixture of normals
hi
i'm looking for a gibbs sampling algorithm for R for the case of mixture of K
normals, and in particular for the case of bivariate normals.
i'd be grateful if anyone could send its own R-routine, at least for the
univariate case.
thank you in advance
matteo
2006 Nov 27
0
EM algorithm for truncated multivariate mixture of normals
I couldn't find a direct answer in CRAN to this question, so I'm asking
with some trepidation. I have a multivariate dataset (data.frame) with
columns that can be expressed as a set of mixed normals (at least I think)
and need to impute values that have constraints (truncated mixture of
normals where the values cannot be below zero). If there isn't a package
that can do this, is there
2007 Feb 23
3
mixture of 2 normals - starting values
Hi,
I have a problem of estimating a mixture of two normal distributions. I
need to find the starting points automatically, since this is a part of a
larger piece of image processing code.
I found the mix2normal1 function in VGAM package that mentions a method of
finding starting values for mu1 and mu2 but refers the reader to a book by
Everitt and Hand. Unfortunately, I do not have an easy
2011 Apr 04
1
Difference in mixture normals and one density
Hello,
I am trying to find out if R can do the following:
I have a mixture of normals say f = 0.2*Normal(2, 5) + 0.8*Normal(3,2)
How do I find the difference in the densities at any particular point of f
and at Normal(2,5)?
--
Thanks,
Jim.
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2002 Oct 22
5
Mixture of Univariate Normals
Dear list,
Can anyone provide a package or code for estimating the parameters of a
mixture of c (c >=2) univariate normal distributions?
I've tried the algorithm provided by Venables & Ripley (1999) p 263, for
the mixture of two normal, but I don't find the "ms" function in R. I've
used nls instead, but I'm not sure if it works the same.
The data I have is very
2009 May 21
1
em algorithm mixture of multivariate normals
Hi,
I would like to know if it is possible to have a "R code" to estimate the
parameters of a mixture of bivariate (or multivariate) normals via EM
Algorithm. I tried to write it, but in the estimation of the matrix of
variance and covariance, i have some problems. I generate two bidimensional
vectors both from different distribution with their own vector means and
variance and
2007 Aug 04
2
Mixture of Normals with Large Data
All:
I am trying to fit a mixture of 2 normals with > 110 million observations. I
am running R 2.5.1 on a box with 1gb RAM running 32-bit windows and I
continue to run out of memory. Does anyone have any suggestions.
Thanks so much,
Tim
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2007 Apr 12
3
Random Sequence
Dear Friends,
I'm trying to generate a sequence of 100 observations
with either a 1 or -1. In other words the sequence
should look something like this.
y = 1 1 -1 1 -1 -1 -1 1 1 ......
Can somebody please give me some direction on how I
can do this in R.
Thanks
Anup
____________________________________________________________________________________
Don't get soaked. Take a
2007 Apr 18
2
Data Manipulation using R
Dear Friends,
I have data set with around 220,000 rows and 17 columns. One of the columns is an id variable which is grouped from 1000 through 9000. I need to perform the following operations.
1) Remove all the observations with id's between 6000 and 6999
I tried using this method.
remdat1 <- subset(data, ID<6000)
remdat2 <- subset(data, ID>=7000)
donedat <- rbind(remdat1,
2007 Jul 06
1
row index
Dear Friends,
Suppose I have a vector as follows
RI Value
1 10
2 11
3 8
4 4
6 12
I would like a function which returns the"row index number" for the minimum value of VALUE. Can somebody please give me some direction on how I can do this. In effect I'm trying to find a comparable function for the GAUSS command "minindc"
>From the GAUSS Manual
2007 Jul 24
1
Passing equations as arguments
Friends,
I'm trying to pass an equation as an argument to a function. The idea is as follows. Let us say i write an independent function
Ideal Situation:
ifunc <- function(x)
{
return((x*x)-2)
}
mainfunc <- function(a,b)
{
evala <- ifunc(a)
evalb <- ifunc(b)
if (evala>evalb){return(evala)}
else
return(evalb)
}
Now I want to try and write this entire program in a single
2007 Sep 08
1
Problem with the aggregate command
Dear friends,
I have a data set with 23 columns and 38000 rows. It is a panel running from the years 1991 through 2005. I want to aggregate the data and get the medians of each of the 23 columns for each of the years. In other words my output should be like this
Year Median
1991 123
1992 145
1993 132
etc.
The sample lines of code to do this operation is
set1 <-
2009 Nov 25
1
fitting mixture of normals distribution to asset return data
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2012 Mar 05
1
Fitting & evaluating mixture of two Weibull distributions
Hello,
I would like to fit a mixture of two Weibull distributions to my data, estimate the model parameters, and compare the fit of the model to that of a single Weibull distribution.
I have used the mix() function in the 'mixdist' package to fit the mixed distribution, and have got the parameter estimates, however, I have not been able to get the log-likelihood for the fit of this model
2008 Aug 12
0
KS Test for Mixture of Distributions
Hi all,
How can we use ks.test() to evaluate
goodness of fit of mixtures of distributions?
For example I have the following dataset:
> x
[1] 176.1 176.8 259.6 171.6 90.0 234.3 145.7 113.7 105.9 176.2 168.9 136.1
[13] 109.2 110.3 164.3 117.7 131.3 163.7 200.4 196.4 196.2 168.6 190.4 127.5
[25] 136.0 114.2 112.0 91.9 333.4 295.5 172.0 293.3 91.7 289.7 118.8 55.1
[37] 161.9 233.9 197.7
2007 Aug 19
1
Creating a data set within a function
Dear Friends,
I'm trying to find if there is a way to automate creation of the design matrix. Suppose we are interested in say running an autoregressive model. The user inputs the following data
myfunAR <- function(y, order)
{.....
......
}
now here y is the data series and order represents the level of the process. In other words if order=2 then we have an AR (2) process. Now it is easy
2007 Jun 04
1
Help with conditional lagging of data
Dear Friends,
I have some data with three columns named ID, Year and Measure X. I need to create a column which gives me a lag for each ID (note not a continous lag), but a lag conditional on the id and the given year. Please find below a sample of the data
Input file sample
ID Year X
AB12 2000 100
AB12 2001 120
AB12 2002 140
AB12 2003 80
BL14 2000 180
BL14
2009 Aug 06
0
Fitting Mixture of Non-Central Student's t Distributions
Dear Ingmar & Dave,
Thanks a lot for your help and sorry for the late reply.
Finally, I've found a way to separate the mixture of distributions
(empirically). But the gamlss package looks great, I'm sure it will help
me during my further studies.
Kind regards,
Susanne
On 15 Jun 2009, at 20:09, Ingmar Visser wrote:
> Dear Susanne & Dave,
>
> The gamlss package family