Displaying 13 results from an estimated 13 matches similar to: "problems with predict in fGarch"
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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2010 Jul 14
0
fGarch: garchFit() with fixed coefficents
hello everybody,
I would like to fit a model to a times series (testing set) for out of
sample predictions using garchFit(). I would like to keep the coefficients
of ARMA/GARCH model fixed (as found by fitting the model to my training
set). The arima fitting function has such an option for that (fixed=NULL)
but the garchFit() doesnt.
It is very important for me to keep the same coefficients
2009 Mar 03
0
Monte carlo simulation in fGARCH
I use fGarch package to estimate AR(1)-ARCH(1) process for a vector of returns. Then, using the estimated parameters I want to simulate 10 000 sample paths where each path has the same length as the vector of returns. So the first line of the code is: spec=garchSpec(model=list(ar= 0.440270860, omega=0.000374365,alpha=0.475446583 , mu=0, beta=0))----
The only way I can think of generating 10 000
2011 Jan 31
0
Applying previously fitted fGarch model
Greetings,
Suppose I fit an fGarch model via garchFit function for a time series X.
I'm wondering is there any easy way to apply the fitted model to a different
time series Y to calculate conditional variances and standardized residuals?
Thanks.
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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(
+
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
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] <-
2009 Feb 17
1
R crash after fGarch update
Hi folks!
After updating my packages my R seems to have completely crashed as will not
start up - even after I installed 2.8.1 from 2.8.0.
I get the following:
Fatal error: unable to restore saved data in .Rdata
Error in loadNamespeace(name): there is no package called fGarch
But I do have a package called fGarch.
After I hit ok, it crashes and exits. I cannot use any functionality at
all.
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 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
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:
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) +