Displaying 20 results from an estimated 3000 matches similar to: "MLE for a t distribution"
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 Apr 14
2
Gaussian Quadrature Numerical Integration In R
Hi All,
I am trying to use A Gaussian quadrature over the interval (-infty,infty) with weighting function W(x)=exp(-(x-mu)^2/sigma) to estimate an integral.
Is there a way to do it in R? Is there a function already implemented which uses such weighting function.
I have been searching in the statmode package and I found the function "gauss.quad(100, kind="hermite")" which uses
2012 Aug 02
1
finding the MLEs of IG parameters by EM-Alorithm
Dear all
I'm trying to caculate the MLEs for parameters of Inverse Gaussian
distribution (in a k-sample problem with common mean) by using
EM-Algorithm. I found some package for EM-Algorithm that are useful
for missing or incomplete data and are not helpful for solving my
problem.
(Exactly, the problem is: Let Xij, i=1,..,k , j=1,...,ni, be a random
sample from IG(?,?i). So the
2011 Nov 06
2
how to use quadrature to integrate some complicated functions
Hello to all,
I am having trouble with intregrating a complicated uni-dimensional function
of the following form
Phi(x-a_1)*Phi(x-a_2)*...*Phi(x-a_{n-1})*phi(x-a_n).
Here n is about 5000, Phi is the cumulative distribution function of
standard normal,
phi is the density function of standard normal, and x ranges over
(-infty,infty).
My idea is to to use quadrature to handle this integral. But
2012 Feb 29
2
Converting a function from Splus to R
I have a function written for Splus, when I run it in R I obtain get an error
because the function has the elements "0.d0" and "2.d0". How can I change it
to run in R?
The function can be found in page 230 from
http://www.stat.wisc.edu/~mchung/teaching/stat471/stat_computing.pdf
Function is as follows:
gauher <- function(n) {# Gauss-Hermite: returns x,w so that
2009 Apr 16
2
there are fontencoding problem in Sweave
I want write article by russian language using Sweave. For cyrillic text
LaTeX use T2A encoding
\usepackage[T2A]{fontenc}
But in Sweave.sty we find:
\RequirePackage[T1]{fontenc}
It is source of critical problem.
For example Rnw file
$ cat estimation.Rnw
\documentclass[A4paper]{article}
\usepackage[T2A]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[russian,english]{babel}
2006 Oct 02
1
Trig.Rd typo (PR#9269)
Full_Name: Robin Hankin
Version: 2.4.0 RC
OS: MacOSX 10.4.7
Submission from: (NULL) (139.166.242.29)
The first cut line described in Trig.Rd for asin() is incorrect in the ascii
version of the manpage.
The Rd file reads:
For \code{asin()} and \code{acos()}, there are two cuts, both along
the real axis: \eqn{\left(-\infty, -1\right]}{\(-Inf, 1\]} and
Note the inconsistency between the
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
2012 May 23
1
numerical integration
Greetings,
Sorry, the last message was sent by mistake! Here it is again:
I encounter a strange problem computing some numerical integrals on [0,oo).
Define
$$
M_j(x)=exp(-jax)
$$
where $a=0.08$. We want to compute the $L^2([0,\infty))$-inner products
$$
A_{ij}:=(M_i,M_j)=\int_0^\infty M_i(x)M_j(x)dx
$$
Analytically we have
$$
A_{ij}=1/(a(i+j)).
$$
In the code below we compute the matrix
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
2006 Nov 18
1
Questions regarding "integrate" function
Hi there. Thanks for your time in advance.
I am using R 2.2.0 and OS: Windows XP.
My final goal is to calculate 1/2*integral of
(f1(x)^1/2-f2(x)^(1/2))^2dx (Latex codes:
$\frac{1}{2}\int^{{\infty}}_{\infty}
(\sqrt{f_1(x)}-\sqrt{f_2(x)})^2dx $.) where f1(x) and f2(x) are two
marginal densities.
My problem:
I have the following R codes using "adapt" package. Although "adapt"
2009 Feb 03
10
Convert mle list to a hash
These patches convert the mle list to a hash. The same patches apply on
ocfs2 1.4 too.
Currently, we use the same number of hash pages for mles and lockres'.
This will be addressed in a future patch that will make both of them
configurable.
Sunil
2010 Sep 21
3
bivariate vector numerical integration with infinite range
Dear list,
I'm seeking some advice regarding a particular numerical integration I
wish to perform.
The integrand f takes two real arguments x and y and returns a vector
of constant length N. The range of integration is [0, infty) for x and
[a,b] (finite) for y. Since the integrand has values in R^N I did not
find a built-in function to perform numerical quadrature, so I wrote
my own after
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
2009 Feb 26
13
o2dlm mle hash patches - round 2
The changes from the last drop are:
1. Patch 11 removes struct dlm_lock_name.
2. Patch 12 is an unrelated bugfix. Actually is related to a bugfix
that we are retracting in mainline currently. The patch may need more testing.
While I did hit the condition in my testing, Marcos hasn't. I am sending it
because it can be queued for 2.6.30. Give us more time to test.
3. Patch 13 will be useful
2004 Jun 10
1
overhaul of mle
So, I've embarked on my threatened modifications to the mle subset
of the stats4 package. Most of what I've done so far has *not* been
adding the slick formula interface, but rather making it work properly
and reasonably robustly with real mle problems -- especially ones
involving reasonably complex fixed and default parameter sets.
Some of what I've done breaks backward
2008 Jan 07
2
chi-squared with zero df (PR#10551)
Full_Name: Jerry W. Lewis
Version: 2.6.1
OS: Windows XP Professional
Submission from: (NULL) (24.147.191.250)
pchisq(0,0,ncp=lambda) returns 0 instead of exp(-lambda/2)
pchisq(x,0,ncp=lambda) returns NaN instead of exp(-lambda/2)*(1 +
SUM_{r=0}^infty ((lambda/2)^r / r!) pchisq(x, df + 2r))
qchisq(.7,0,ncp=1) returns 1.712252 instead of 0.701297103
qchisq(exp(-1/2),0,ncp=1) returns 1.238938
2008 Mar 12
3
Types of quadrature
Dear R-users
I would like to integrate something like \int_k^\infty (1 - F(x)) dx, where F(.) is a cumulative distribution function. As mentioned in the "integrate" help-page: integrate(dnorm,0,20000) ## fails on many systems. This does not happen for an adaptive Simpson or Lobatto quadrature (cf. Matlab). Even though I am hardly familiar with numerical integration the implementation
2009 Feb 26
1
gplot problems with faceting
Dear R-Listers,
I am very confused with what seems to be a misuse of the faceting options with gplot function and I hope you might help me on this.
z contains various simulation results from simulations with different set of parameters.
I melt my data to have the following data.frame structure :
> str(z)
'data.frame': 12383 obs. of 5 variables:
$ vID : num 1 2 3 4 5 6 7 8
2002 Dec 01
1
SYSLINUX COM32 example in assembly (NASM)
Hello
Where can I get example in assembly, using COM32 API ?
I'm trying to make simple "Hello World" using COM32, but this code does not
works 8-(
org 0x101000 ; this number I get from comboot.doc
_start:
mov ecx,msge-msg
mov ebx,msg
mov ah,0x02
.L:
mov dl, byte [ebx]
inc ebx
int 0x21
loop .L
.Z: jmp .Z ; \infty loop
msg: db "Hello World !"
msge: