Displaying 20 results from an estimated 2000 matches similar to: "fGarch: garchFit() with fixed coefficents"
2009 Jun 30
1
garchFit in fGarch fitted values are all the same
Dear all-
Package /fGarch/ version 2100.78 in R version 2.8.1 (2008-12-22)
running on linux 2.6.22.9-91.fc7
In trying to fit garch models in above environment. I am getting
"reasonable" fitted coefficients, but the fitObject@fitted are all the
same. This is true even for the help page example:
library(fGarch)
R> X.timeSeries = as.timeSeries(msft.dat)
R> head(
+
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] <-
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
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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) +
2011 Nov 06
0
fGarch: garchFit and include.shape/shape parameters
Hello,
The function garchFit in the package fGarch allows for choosing a
conditional distribution, one of which is the t-distribution. The function
allows specification of the shape parameter of the distribution (equal to
the degrees of freedom for the t-distribution), for which the default is set
to 4. The function also includes an option "include.shape", which is "a
logical flag
2013 Feb 17
0
forecast ARMA(1,1)/GARCH(1,1) using fGarch library
Hi, i am working in the forecast of the daily price crude .
The last prices of this data are the following:
100.60 101.47 100.20 100.06 98.68 101.28 101.05 102.13 101.70 98.27
101.00 100.50 100.03 102.23 102.68 103.32 102.67 102.23 102.14 101.25
101.11 99.90 98.53 96.76 96.12 96.54 96.30 95.92 95.92 93.45
93.71 96.42 93.99 93.76 95.24 95.63 95.95 95.83 95.65
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:
2008 Mar 24
0
ARCH(1,0) with t-residuals
Dear R users,
I need to estimate an ARCH(1,0) model with t-residuals. To do this I use garchFit
function from fGarch library. However, I get the following error message:
Error in.garchInitParameters (formula.mean = formula.mean, formula.var =
formula.var, ): object "alpha" not found
I tried to estimate this model with different series, but I always get this error message.
For example,
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 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 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 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
2011 Jul 27
0
problems with predict in fGarch
Hello I am trying to use predict from an arma-Garch model (arma(2, 2) +
garch(1, 1)) and I am getting the following error:
Error en arima(x = object@data, order = c(max(u, 1), 0, max(v, 1)), init =
c(ar, :
non-stationary AR part from CSS
Does anybody know what can be the reason of this error? The model I have
estimated is the following:
Title:
GARCH Modelling
Call:
garchFit(formula =
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
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
2013 Apr 08
0
Maximum likelihood estimation of ARMA(1,1)-GARCH(1,1)
Hello
Following some standard textbooks on ARMA(1,1)-GARCH(1,1) (e.g. Ruey
Tsay's Analysis of Financial Time Series), I try to write an R program
to estimate the key parameters of an ARMA(1,1)-GARCH(1,1) model for
Intel's stock returns. For some random reason, I cannot decipher what
is wrong with my R program. The R package fGarch already gives me the
answer, but my customized function
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 May 10
0
DCC-GARCH model and AR(1)-GARCH(1, 1) regression model - help needed..
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 =
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
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 =