Displaying 20 results from an estimated 11000 matches similar to: "GARCH AIC"
2008 Nov 04
1
AIC in time series
Hi everybody,
I have fitted an ar(1),Garch(1,1) model to some observations with the
help of the garchFit function which is in the fGarch package. Here
what I've done:
library("fGarch")
fit = garchFit(formula=~ar(1)+~garch(1,1), data=garat)
Now I want to count AIC for this model. How can I do it? I cannot do
it with the AIC function of stats package, because R tells me:
"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
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 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:
>
2011 May 15
4
DCC-GARCH model
Hello,
I have a few questions concerning the DCC-GARCH model and its programming in
R.
So here is what I want to do:
I take quotes of two indices - S&P500 and DJ. And the aim is to estimate
coefficients of the DCC-GARCH model for them. This is how I do it:
library(tseries)
p1 = get.hist.quote(instrument = "^gspc",start = "2005-01-07",end =
2009 Jun 19
1
using garchFit() to fit ARMA+GARCH model with exogeneous variables
Hello -
Here's what I'm trying to do. I want to fit a time series y with
ARMA(1,1) + GARCH(1,1), there are also an exogeneous variable x which I
wish to include, so the whole equation looks like:
y_t - \phi y_{t-1} = \sigma_t \epsilon_t + \theta \sigma_{t-1}
\epsilon_{t-1} + c x_t where \epsilon_t are i.i.d. random
variables
\sigma_t^2 = omega + \alpha \sigma_{t-1}^2 + \beta
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
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] <-
2011 Nov 20
1
alpha_1 + beta_1 >1 in GARCH(1,1)
Hi,
as i suppose to know in a stationary GARCH(1,1) model the sum of alpha and
beta has to be smaller than 1.
But if i use the garchfit() function from the package fGarch for my
timeseries the sum is bigger than 1.
The adf.test tells me a p-value smaller than 0.01 instead.
What does this mean for me?
Can i trust in the coefficients in this case?
mfg user84
--
View this message in context:
2011 May 12
2
DCC-GARCH model and AR(1)-GARCH(1,1) regression model
Hello,
I have a rather complex problem... I will have to explain everything in
detail because I cannot solve it by myself...i just ran out of ideas. So
here is what I want to do:
I take quotes of two indices - S&P500 and DJ. And my first aim is to
estimate coefficients of the DCC-GARCH model for them. This is how I do it:
library(tseries)
p1 = get.hist.quote(instrument =
2011 Sep 28
1
fGarch - Fitting and APARCH-Modell with fixed delta
Hi there,
I'm trying to fit a GJR-GARCH Model using fGarch. I wanted to try that by
fitting an APARCH model with a fixed delta of 2 and a non-fixed gamma. So I
was simply trying to use:
spec <- garchFit(~aparch(1,1),data=garchSim(),delta=2)
coef(spec)
And sometimes, it's working like a charm and delta is indeed exactly 2 in
the resulting coefficient vector.
Frequently, though, the
2010 Dec 07
1
Using nlminb for maximum likelihood estimation
I'm trying to estimate the parameters for GARCH(1,1) process.
Here's my code:
loglikelihood <-function(theta) {
h=((r[1]-theta[1])^2)
p=0
for (t in 2:length(r)) {
h=c(h,theta[2]+theta[3]*((r[t-1]-theta[1])^2)+theta[4]*h[t-1])
p=c(p,dnorm(r[t],theta[1],sqrt(h[t]),log=TRUE))
}
-sum(p)
}
Then I use nlminb to minimize the function loglikelihood:
nlminb(
2012 Oct 11
1
a question
Dear R-helpers,
I need to read some data from output of garchFit in fGarch.
my model is garch(1,1) and i want to read
coefficients(omega,alpha,beta) and timeseries(x) and conditional
SD(s). because i need them to use in other formula.
for example :omega+x[1]+s[3]
and maybe i have several simulation then i need a general way to read
them, not to read with my eyes for example the quantity of
2011 Jul 13
1
AR-GARCH with additional variable - estimation problem
Dear list members,
I am trying to estimate parameters of the AR(1)-GARCH(1,1) model. I have one
additional dummy variable for the AR(1) part.
First I wanted to do it using garchFit function (everything would be then
estimated in one step) however in the fGarch library I didn't find a way to
include an additional variable.
That would be the formula but, as said, I think it is impossible to add
2008 Dec 30
1
A mistake in garchFit()? {fGarch}
Hello,
I was using garchFit {fGarch} to fit some GARCH processes.
I noticed that the result contains "Log Likelihood" value (right above
"Description"), but when I use .. at fit$llh to retrieve Log Likelihood value,
the sign switched.
I am confused about which value I should choose to report...
Any help here?
Thanks a lot!
Ted
--
View this message in context:
2011 Mar 24
1
Problems with predict in fGarch
Hello. I am using fGarch to estimate the following model:
Call:
garchFit(formula = fmla, data = X[, i], trace = F)
Mean and Variance Equation:
data ~ arma(1, 1) + garch(1, 1)
Conditional Distribution:
norm
Coefficient(s):
mu ar1 ma1 omega alpha1 beta1
-0.94934 1.00000 -0.23211 54.06402 0.45709 0.61738
Std. Errors:
based on Hessian
Error Analysis:
2012 Mar 11
0
specify GARCH model, using garchFit()
Hello,
I’ve fitted a Garch(2,1) model with function 'garchFit()' from the package
'fGarch':
> m1 <- garchFit(formula = ~garch(2,1),data = X,trace = F)
* See 'summary(m1)' OUTPUT BELOW *
PROBLEM: My alpha1 term is not significant and I would like to make a NEW
model, say m2, that does not contain alpha1, but I am not sure how to
specify this with the garchFit()
2009 Apr 06
1
Problem with Extracting Fitted Values from fGarch package
Good day everyone,
I fitted a GARCH model to a time series and R estimated the model and provide me with the estimates. However, when I tried to extract the fitted values from the estimated model I got the following error message:
"Error in .local(object, ...) : object "fit" not found"
I used the following to extract the fitted values
fitted_TASI <- fitted(garchFit(~
2011 Feb 15
1
Estimation of an GARCH model with conditional skewness and kurtosis
Hello,
I'm quite new to R but tried to learn as much as possible in the last
few months.
My problem is that I would like to estimate the model of Leon et al. (2005).
I have shortly summarised the most important equations in the following
pdf file:
http://hannes.fedorapeople.org/leon2005.pdf
My main question is now how could I introduce these two additional terms
into the Likelihood