Displaying 20 results from an estimated 1000 matches similar to: "finding the MLEs of IG parameters by EM-Alorithm"
2012 Feb 06
1
MLEs using optim
I am trying to use the optim command to get the MLEs for a number of
parameters based on some data. Is it possible to write a program that
maximizes the likelihood and stores the parameters (many times)? I need to
do this a lot of times, each time the data will be updated with more entries
(rows). I need to see how the new data is affecting the previous parameter
estimates of the model. What is
2019 May 26
2
rbind has confusing result for custom sub-class (possible bug?)
On Sun, May 26, 2019 at 4:06 AM Michael Chirico
<michaelchirico4 at gmail.com> wrote:
>
> Have finally managed to come up with a fix after checking out sys.calls()
> from within the as.Date.IDate debugger, which shows something like:
>
> [[1]] rbind(DF, DF)
> [[2]] rbind(deparse.level, ...)
> [[3]] `[<-`(`*tmp*`, ri, value = 18042L)
> [[4]] `[<-.Date`(`*tmp*`,
2019 May 27
2
rbind has confusing result for custom sub-class (possible bug?)
Yes, thanks for following up on thread here. And thanks again for clearing
things up, your email was a finger snap of clarity on the whole issue.
I'll add that actually it was data.table's code at fault on the storage
conversion -- note that if you use an arbitrary sub-class 'foo' with no
methods defined, it'll stay integer.
That's because [<- calls as.Date and then
2019 Jun 02
1
rbind has confusing result for custom sub-class (possible bug?)
I thought it would be good to summarize my thoughts, since I made a
few hypotheses that turned out to be false.
This isn't a bug in base R, in either rbind() or `[<-.Date`.
To summarize the root cause:
base::rbind.data.frame() calls `[<-` for each column of the
data.frame, and there is no `[<-.IDate` method to ensure the
replacement value is converted to integer. And, in fact,
2010 Aug 05
1
rbind on data.frame that contains a column that is also a data.frame
Hi,
The following was already a topic on r-help, but after understanding what is
going on, I think it fits better in r-devel.
The problem is this:
When a data.frame has another data.frame in it, rbind doesn't work well.
Here is an example:
--
> a=data.frame(x=1:10,y=1:10)
> b=data.frame(z=1:10)
> b$a=a
> b
z a.x a.y
1 1 1 1
2 2 2 2
3 3 3 3
4 4 4 4
5
2007 Jul 21
1
Gamma MLE
Hello,
I was asked to try the following code on R,
gamma.mles
function (xx,shape0,rate0)
{
n<- length(xx)
xbar<- mean(xx)
logxbar<- mean(log(xx))
theta<-c(shape0,rate0)
repeat {
theta0<- theta
shape<- theta0[1]
rate<- theta0[2]
S<- n*matrix(c(log(rate)-digamma(shape)+logxbar,shape/rate-xbar),ncol=1)
I<- n*matrix(c(trigamma(shape),-1/rate,-1/rate,shape/rate^2),ncol=2)
2010 Mar 26
2
R loop help
Hi,
I am tring to write a loop to compute this,
==========================
x1=c(
rep(-1,4),
rep(1,4)
)
x2=c(
rep(c(-1,-1,1,1),2)
)
x3=c(
rep(c(-1,1),4)
)
x1*x2
x1*x3
x2*x3
========================
suppose i have x1,x2,x3
i want to compute their ' two factor interactions', x1x2,x1x3 and x2x3,
I wrote
========================
for(i in 1:2){
for( j in i+1:3){
xij=c()
2009 Dec 10
1
MLE for a t distribution
Given X1,...,Xn ~ t_k(mu,sigma) student t distribution with k degrees
of freedom, mean mu and standard deviation sigma, I want to obtain the
MLEs of the three parameters (mu, sigma and k). When I try traditional
optimization techniques I don't find the MLEs. Usually I just get
k->infty. Does anybody know of any algorithms/functions in R that can
help me obtain the MLEs? I am especially
2006 Oct 17
1
About compositional data analysis
The compositional data xi=(x_i1,x_i2,...,x_in), for each fixed i , xij>0,
and sum(xij)=1;
I want to compare the mean( u_i) of several groups
i.e.
H0: u_1=u_2=...=u_N
or
H0: u_11=u_21=...=u_N1
Are there any ANOVA tpye tools to do this work in R?
Thanks,
WEN S Q
[[alternative HTML version deleted]]
2020 Oct 09
1
Aide pour finaliser ce code
Hello.
Here is my R code. I used the functional data . Now I need to use the
functional data by applying the kernels instead of the xi, yi functions.
Bonjour.
Voici mon code en R . J'ai utiliser les donn?es fonctionnelles . Maintenant
j'ai besoin d'utiliser les donn?es fonctionnelles en appliquant les noyaux
? la place des fontions xi, yi
library(MASS)
2020 Oct 10
3
Please need help to finalize my code
Good evening dear administrators,
It is with pleasure that I am writing to you to ask for help to finalize my
R programming algorithm.
Indeed, I attach this note to my code which deals with a case of
independence test statistic . My request is to introduce the kernels using
the functional data for this same code that I am sending you. So I list the
lines for which we need to introduce the
2006 Aug 24
1
Optim question
This is a very basic question, but I am a bit confused with optim. I
want to get the MLEs using optim which could replace the newton-raphson
code I have below which also gives the MLEs. The function takes as input
a vector x denoting whether a respondent answered an item correctly
(x=1) or not (x=0). It also takes as input a vector b_vector, and these
are parameters of test items (Rasch estimates
2005 Feb 15
2
how many 7th of the month is there between two dates
This is a eaeir way to ask my prior question:
I want to caculate how many an exact day of the month there is between
two dates.
For example; How many 7th of the month is there between "1998/12/17"
and "2000/1/7". To make the problem simple, the day of the month (7)
is the day in the 2nd date.
2020 Oct 13
1
Please need help to finalize my code
Hm. Google tells me that kernel function is in stats package which comes with base installation and is invoked when you start R.
search()
[1] ".GlobalEnv" "package:stats" "package:graphics"
[4] "package:grDevices" "package:utils" "package:datasets"
[7] "package:methods" "Autoloads"
2008 Feb 15
1
Questions about EM algorithm
Dear all:
Assume I have 3 distributions, x1, x2, and x3.
x1 ~ normal(mu1, sd1)
x2 ~ normal(mu2, sd2)
x3 ~ normal(mu3, sd3)
y1 = x1 + x2
y2 = x1 + x3
Now that the data I can observed is only y1 and y2. It is
easy to estimate (mu1+m2), (mu1+mu3), (sd1^2+sd2^2) and
(sd1^2+sd3^2) by EM algorithm since
y1 ~ normal(mu1+mu2, sqrt(sd1^2+sd2^2)) and
y2 ~ normal(mu1+mu3, sqrt(sd1^2+sd3^2))
However, I want
2020 Oct 13
0
Please need help to finalize my code
What do you *mean* "when you want to use the kernels".
WHICH kernels?
Use to do WHAT?
In your browser, visit cran.r-project.org
then select "Packages" from the list on the left.
Then pick the alphabetic list.
Now search for 'kernel'.
You will find dozens of matches.
On Wed, 14 Oct 2020 at 05:15, PIKAL Petr <petr.pikal at precheza.cz> wrote:
> Hm. Google tells
2010 Jan 02
4
caculate the frequencies of the Amino Acids
may some one please help me to sort this out, i am trying to writ a R code
for calculating the frequencies of the amino acids in 9 different sequences,
i want the code to read the sequence from external text file, i used the
following code to do so:
x<-read.table("sequence.txt",header=FALSE)
then i defined an array for 20 amino acids as following:
2010 Jun 17
2
Pretty printing progress
I have a function that is an iterative process for estimating some MLEs. I want to print some progress to screen as the process iterates. I would like to try and line things up nicely in the R window, but am not sure the best way to do this. Below is a toy example. Suppose I want the value of 10 to be just below "iteration" and the value of -1234 to be just below 'Log
2012 Apr 06
2
Sincere inquiry about “subscript out of bounds” error in R
Hello£¬experts
I am working on a simulation of effect of artificial selection on certain population in Animal Breeding.I am new beginner in coding. I have already build a matrix A(500*500) based on this code
A<-matrix(,500,500)
for(i in 1:500){
for(j in 1:500){
ifelse(i==j,A[i,j]<-1,A[i,j]<-0)
}
}
and I need to caculate A2
base on A and X1(4500*4500).Here are the codes
2013 Sep 02
2
Backend for Lucene format indexes-How to get doclength
On Mon, Sep 02, 2013 at 09:21:48AM +0800, jiangwen jiang wrote:
> TfIdfWeight and BM25(b=0) also need wdf_upper_bound, it is not exists in
> Lucene backends.
If you don't provide an implementation of wdf_upper_bound(), the default
is to use the collection frequency of the term, so provided that
information is available in the lucene files, the lack of
wdf_upper_bound information