Displaying 20 results from an estimated 1000 matches similar to: "Using nlminb for maximum likelihood estimation"
2011 Jan 21
3
nlminb doesn't converge and produce a warning
Hi Everybody,
My problem is that nlminb doesn't converge, in minimising a logLikelihood
function, with 31*6 parameters(2 weibull parameters+29 regressors repeated 6
times).
I use nlminb like this :
res1<-nlminb(vect, V, lower=c(rep(0.01, 12), rep(0.01, 3), rep(-Inf, n-15)),
upper=c(rep(Inf, 12), rep(0.99, 3), rep(Inf, n-15)), control =
list(maxit=1000) )
and that's the result :
2010 Dec 08
1
Error in eval.with.vis(expr, envir, enclos) : subscript out of bounds
I have a for-loop in my code that calls another .R file:
source("estimation.R")
This file runs through without any problems, so the program completes the loop one time. However, when the loop starts a second time and it comes time to call the file "estimation.R" again, program stops and prints the following error message:
"Error in eval.with.vis(expr, envir, enclos) :
2006 Jul 06
1
Problem with garchFit function in fSeries
I used garchFit function to fit 1600 observations of EURO/USD 2-day returns
in GARCH(1,1) model.
As part of the summary I got warning message:
NaNs produced in: sqrt(diag(fit$cvar))
And didn't get any estimates for 3 params' std.error, t value or
probability:
Error Analysis:
Estimate Std. Error t value Pr(>|t|)
mu -0.004827 0.020141 -0.240 0.811
ar1 0.010311
2008 Mar 19
1
betabinomial model
Hi,
can anyone help me fit betabinomial model to the following dataset where
each iD is a cluster in itself , if i use package aod 's betabinom model it
gives an estimate of zero to phi(the correlation coeficient ) and if i fix
it to the anova type estimate obtained from icc( in package aod) then it
says system is exactly singular. And when i try to fit my loglikelihood by
2006 Nov 22
2
problems with garchFit
Hi all,
I post it on both r-help and r-finance since I don't know where is most
appropriate for this topic. Sorry if it bothers you.
I did garch fitting on S&P500 monthly returns with garchFit from fSeries. I
got same coefficients from all cond.dist except normal. I thought that is
probabaly usual for the data. But when I play with it, I got another
question.
I plot skew normal with
2011 May 04
1
fGarch
Hi,
I am attempting to fit a ARMA/GARCH regression model without success.
### ARIMA-GARCH model with regressor ###
### Time series data: A multivariate data set.
cov.ts.dq = cov.ts[1:4,"dq1"][!is.na(cov.ts[,"dq1"])]
cov.ts.day = ts.intersect(dq = diff(q.ts), day = lag(q.ts, -1))
### The following R scripts work:
(summary(no.day.fitr <- garchFit(dq ~ arma(0,3) +
2007 Dec 12
1
APARCH
Hi,
Could somebody say if it is possible to compute APARCH-models with garchFit
commands.
I have earlier used aaa (garchOxFit) and now I try to use bbb (look below)
aaa <-
garchOxFit(formula.mean=~arma(1,0),formula.var=~aparch(1,1),series=nyk,cond.dist=c('gaussian'))
bbb <- garchFit(formula=~arma(1,0)+aparch(1,1),data=nyk)
aaa works well, but I need other characteristics of
2007 Jan 06
1
garchFit in R
Dear all,
I have problem here :
I'm using garchFit from fSeries package, here is part of the script :
> data <- read.table("d:/data.txt")
> a <- garchFit(~garch(1,1),ts(data))
I also attached the file here. In my experience, I got my R not responding.
I also tried with
> a <- garchFit(~garch(1,1),ts(data*10))
and it's worked.
I
2009 Apr 29
1
arma model with garch errors
Dear R experts,
I am trying to estimate an ARMA 2,2 model with garch errors.
I used the following code on R 2.9.
#library
library(fGarch)
#data
data1<-ts(read.table("C:/Users/falcon/Desktop/Time
Series/exports/goods1.csv"), start=c(1992,1), frequency=12)
head(data1)
#garch
garchFit(formula.mean= ~arma(2,2),formula.var=~garch(1,1), data=data1)
but get this error:
>
2010 Mar 17
1
Reg GARCH+ARIMA
Hi,
Although my doubt is pretty,as i m not from stats background i am not sure
how to proceed on this.
Currently i am doing a forecasting.I used ARIMA to forecast and time series
was volatile i used garchFit for residuals.
How to use the output of Garch to correct the forecasted values from ARIMA.
Here is my code:
###delta is the data
fit<-arima(delta,order=c(2,,0,1))
fit.res <-
2008 Apr 01
1
garch prediction
Hello
I want to predict the future values of time series with Garch
When I specified my model like this:
library(fGarch)
ret <- diff(log(x))*100
fit = garchFit(~arma(1,0,0)+garch(1, 1), data =ret)
predict(fit, n.ahead = 10)
meanForecast meanError standardDeviation
1 0.01371299 0.03086350 0.03305819
2 0.01211893 0.03094519 0.03350248
2005 Dec 13
1
fSeries
I'm trying to use garchFit from fSeries, with Student or Skewed Student conditionnal distribution. Let's say that eps (vector) is my series of daily log-returns:
data(EuStockMarkets)
eps = diff(log(EuStockMarkets[,"CAC"]))
library(fSeries)
g = garchFit(series = eps, formula.var = ~garch(2,2), cond.dist = "dstd")
s = g at fit$series
All the coefficients are ok
2004 Nov 10
2
fSeries
Good morning everyone,
I use for the first time the package fSeries and i try to run the example
given by Diethelm Würtz. But when i run its example which is the following
#
# Example:
# Model a GARCH time series process
#
# Description:
# PART I: Estimate GARCH models of the following type ARCH(2)
# and GARCH(1,1) with normal conditional distribution functions.
# PART II: Simulate
2006 Sep 02
1
nonlinear least squares fitting Trust-Region"
Dear Mr Graves,
Thank you very much for your response. Nobody else from this mailing list ventured to reply to me for the two weeks since I posted my question.
"nlminb" and "optim" are just optimization procedures. What I need is not just optimization, but a nonlinear CURVE FITTING procedure. If there is some way to perform nonlinear curve fitting with the
2008 Aug 18
1
another GARCH problem
Hallo,
i want to fit a GARCH model with a extern regressor (without arma
components), so i found the following function in package fGarch. I tryed
out a lot of things but usually I get this Error.
> garchFit(formula=y~x, formula.var=~garch(1,1),data=w)
Error in .garchFit(formula.mean, formula.var, series = x, init.rec, delta,
:
Algorithm only supported for mci Recursion
I think i use the
2009 Nov 06
1
GARCH Models in R
Dear all,
I'm using garchFit from fSeries package and I am not getting the desired
results (error message : could not find function "garchFit" ).
Would you please advise as to how I can build an ARIMA(p, d, q) -
GARCH(p,q) model using R
see the attached data and R-output.
Thanking you in advance
Kind regards
Mangalani Peter Makananisa
Statistical Analyst
South
2008 Jun 16
1
Error in maximum likelihood estimation.
Dear UseRs,
I wrote the following function to use MLE.
---------------------------------------------
mlog <- function(theta, nx = 1, nz = 1, dt){
beta <- matrix(theta[1:(nx+1)], ncol = 1)
delta <- matrix(theta[(nx+2):(nx+nz+1)], ncol = 1)
sigma2 <- theta[nx+nz+2]
gamma <- theta[nx+nz+3]
y <- as.matrix(dt[, 1], ncol = 1)
x <- as.matrix(data.frame(1,
2008 Aug 18
1
ARMA(0,2) & GARCH(1,1) - code & hessian
Hello R-list-members,
I'm trying to model ARMA(0,2) & GARCH(1,1) process using the code below, but according to my textbook, the estimated parameters are wrong. The MA-parameters should be negative. (I've got the same problem using garchFit()). Can anyone tell me what I'm doing wrong? And how can I calculate the hessian matrix?
Many thanks,
Desislava Kavrakova
Code:
2006 Apr 26
1
garchFit from fSeries
Dear R People:
I'm trying to use the garchFit function from the library(fSeries)
However, R freezes every time that I use it.
Is anyone else having this problem, please?
Thanks in advance!
R Version 2.2.1 Windows.
Sincerely,
Erin Hodgess
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston - Downtown
mailto: hodgess at gator.uhd.edu
2010 Aug 15
2
fGarch: how to use garchFit() in loop?
Dear expeRts,
How can I specify the order p,q of a GARCH(p,q) model within a loop? Here's a minimal example showing that an "Formula and data units do not match"-error appears:
library(fGarch)
spec <- garchSpec(model = list(alpha = 0.1, beta = c(0.4, 0.4)))
data <- garchSim(spec, n = 100)
x <- list()
for(q in 1:3){
print(q)
x[q] <-