Displaying 20 results from an estimated 6000 matches similar to: "maxLik package."
2009 May 16
1
maxLik pakage
Hi all;
I recently have been used 'maxLik' function for maximizing G2StNV178 function with gradient function gradlik; for receiving this goal, I write the following program; but I have been seen an error in calling gradient function;
The maxLik function can't enter gradlik function (definition of gradient function); I guess my mistake is in line ******** ,that the vector ‘h’ is
2009 Mar 02
1
initial gradient and vmmin not finite
Dear Rhelpers
I have the problem with initial values, could you please tell me how to solve it?
Thank you
June
> p = summary(maxLik(fr,start=c(0,0,0,1,0,-25,-0.2)))
Error in maxRoutine(fn = logLik, grad = grad, hess = hess, start = start, :
NA in the initial gradient
> p = summary(maxLik(fr,start=c(0,0,0,1,0,-25,-0.2),method="BFGS"))
Error in optim(start, func, gr =
2010 Mar 12
2
Question regarding to maxNR
Hi R-users,
Recently, I use maxNR function to find maximizer. I have error appears as follows
Error in maxNRCompute(fn = fn, grad = grad, hess = hess, start = start, :
NA in the initial gradient
My code is
mu=2
s=1
n=300
library(maxLik)
set.seed(1004)
x<-rcauchy(n,mu,s)
loglik<-function(mu)
{
log(prod(dcauchy(x,mu,s)))
}
maxNR(loglik,start=median(x))$estimate
Does anyone know how
2011 Apr 08
1
Estimates at each iteration
Dear Sir\ Madam
I am trying to maximise a complicated loglikelihood function via EM algorithm
which consists of two step "E-step and M-step"and in this case I need to
maximize the expected of like lihood function " which I get from E- step" and
take those estimates of parameter to update the E-step and repate these till
convargence has been met. So I need to know if I
2009 Apr 10
1
Re MLE Issues
Hi
I have been having issue with a ML estimator for Jump diffusion process but
know I am get little error I didn't notice before like I am try to create a
vector
> #GBMPJ MLE Combined Ph 1 LR
> #
> n<-length(combinedlrph1)
> j<-c(1,2,3,4,5,6,7,8,9,10)
Error in c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10) :
unused argument(s) (3, 4, 5, 6, 7, 8, 9, 10)
>
2007 Apr 09
1
R:Maximum likelihood estimation using BHHH and BFGS
Dear R users,
I am new to R. I would like to find *maximum likelihood estimators for psi
and alpha* based on the following *log likelihood function*, c is
consumption data comprising 148 entries:
fn<-function(c,psi,alpha)
{
s1<-sum(for(i in 1:n){(c[i]-(psi^(-1/alpha)*(lag(c[i],-1))))^2*
(lag(c[i],-1)^((-2)*(alpha+1))
)});
s2<- sum(for(m in 1:n){log(lag(c[m],-1)^(((2)*alpha)+2))});
2009 Apr 03
2
Geometric Brownian Motion Process with Jumps
Hi,
I have been using maxLik to do some MLE of Geometric Brownian Motion Process and everything has been going fine, but know I have tried to do it with jumps. I have create a vector of jumps and then added this into my log-likelihood equation, know I am getting a message:
NA in the initial gradient
My codes is hear
#
n<-length(combinedlr)
j<-c(1,2,3,4,5,6,7,8,9,10)
2011 May 03
3
help with the maxBHHH routine
Hello R community,
I have been using R's inbuilt maximum likelihood functions, for the
different methods (NR, BFGS, etc).
I have figured out how to use all of them except the maxBHHH function. This
one is different from the others as it requires an observation level
gradient.
I am using the following syntax:
maxBHHH(logLik,grad=nuGradient,finalHessian="BHHH",start=prm,iterlim=2)
2013 Mar 10
0
Steepest Ascent Algorithm
I am trying to code a steepest ascent algorithm to optimize parameters used
in a survivor function type problem. My unknown parameters (alpha, Beta0,
and Beta1) for which I have been able to optimize using Newton's method. I
keep getting an error because my alpha becomes negative and I can't
calculate the likelihood.
Here is my log likelihood I am optimizing (in LaTex):
l=\sum _{ i=1 }^{
2009 May 11
1
maxLik package
Hi all.
Recently i have been used maxlik package for optimizing a function with 5 parameters but i couldn't define gradient argument in function maxLik;
How i can define a command to receive my goal? Whether I can change the core of this package?
Thanks for your attention and reply
A. kheradmandi
[[alternative HTML version deleted]]
2010 Oct 01
1
Place constrictions on parameters when using Optim and MaxLik
Hi R users,
I am trying to restrct the range of two of the parameters in a maximization
problem. Both parameters should be between -1 and 1. As far as I know, if
I choose the estimation method ="L-BFGS-B" under Optim, I can restrict the
parameter space. However, the "L-BFGS-B" always require finite values of
the loglik function and cannot get around of the problem if an
2010 Mar 27
1
R runs in a usual way, but simulations are not performed
Dear addresses, I need perform a batch of 10 000 simulations for each of
4 options considered. (The idea is to obtain the parameter estimates in
a heteroskedastic linear regression model - with additive or mixed
heteroskedasticity - via the Kenward-Roger small-sample adjusted
covariance matrix of disturbances). For this purpose I wrote an R
program which would capture all possible options (true
2018 Mar 20
0
Struggling to compute marginal effects !
In that case, I can't work out why the first model fails but not the
second. I would start looking at "Data" to see what it contains. if:
object2 <- polr(Inc ~ Training ,Data,Hess = T,method = "logistic" )
works, the problem may be with the "Adopt" variable.
Jim
On Tue, Mar 20, 2018 at 10:55 AM, Willy Byamungu
<wmulimbi at email.uark.edu> wrote:
>
2010 May 10
2
Robust SE & Heteroskedasticity-consistent estimation
Hi,
I'm using maxlik with functions specified (L, his gradient & hessian).
Now I would like determine some robust standard errors of my estimators.
So I 'm try to use vcovHC, or hccm or robcov for example
but in use one of them with my result of maxlik, I've a the following
error message :
Erreur dans terms.default(object) : no terms component
Is there some attributes
2011 Sep 05
3
function censReg in panel data setting
Hello all,
I have a problem estimating Random Effects model using censReg function.
small part of code:
UpC <- censReg(Power ~ Windspeed, left = -Inf, right =
2000,data=PData_In,method="BHHH",nGHQ = 4)
Error in maxNRCompute(fn = logLikAttr, fnOrig = fn, gradOrig = grad,
hessOrig = hess, :
NA in the initial gradient
...then I tried to set starting values myself and here is
2008 Mar 07
0
Packages micEcon, sampleSelection, and maxLik
Dear R Users:
We have splitted up the micEcon package into three packages:
a) Package "maxLik" provides tools for maximum likelihood estimations
(see http://www.maxLik.org).
b) Package "sampleSelection" provides tools for estimating Heckman-type sample
selection/generalized tobit models (see http://www.sampleSelection.org).
c) Package "micEcon" contains the
2008 Mar 07
0
Packages micEcon, sampleSelection, and maxLik
Dear R Users:
We have splitted up the micEcon package into three packages:
a) Package "maxLik" provides tools for maximum likelihood estimations
(see http://www.maxLik.org).
b) Package "sampleSelection" provides tools for estimating Heckman-type sample
selection/generalized tobit models (see http://www.sampleSelection.org).
c) Package "micEcon" contains the
2010 Sep 14
2
Can I monitor the iterative/convergence process while using Optim or MaxLik?
Hi R-helpers,
Is it possible that I have the estimates from each step/iteration shown on
the computer screen in order to monitor the process while I am using Optim
or MaxLik?
Thanks for your help.
Maomao
[[alternative HTML version deleted]]
2010 Aug 28
1
maxNR in maxLik package never stops
Greetings,
I use maxNR function under maxLik package to find the REML estimates of the parameters of variance components in heteroskedastic linear regression models. I assume that in the model there is additive/multiplicative/mixed heteroskedasticity and I need estimate the respective parameters of additive/multiplicative/mixed variance components.
For my research purposes I make a
2012 Dec 20
1
Problem with simulation
Dear:
I am having problem with simulation. Sometimes for 100 iteration, my
program works but sometimes give error message regarding some "built-in
function" which I never used
in my code. I have no idea about the problem. Any suggestion, comments or
idea regarding this would be highly appreciable. Thanks.
I have used ---- "maxLik()" and "BBsolve()" in my code. Error