Displaying 20 results from an estimated 60000 matches similar to: "Need R-help"
2006 Apr 24
2
garch warning
Dear r users,
Few days ago I posted the same topic but unable to receive any suggestion. So I am asking this same question.
I was trying to fit a garch(1,1) model to my dataset. But while executing I got a warning message "NaNs produced in: sqrt(pred$e)". And got the estimated sd's along with five "NA", but as per my best knowledge I should get only one
2006 Jun 13
2
Garch Warning
Dear all R-users,
I wanted to fit a Garch(1,1) model to a dataset by:
>garch1 = garch(na.omit(dat))
But I got a warning message while executing, which is:
>Warning message:
>NaNs produced in: sqrt(pred$e)
The garch parameters that I got are:
> garch1
Call:
garch(x = na.omit(dat))
Coefficient(s):
a0 a1 b1
1.212e-04 1.001e+00 1.111e-14
Can any one
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
2011 Nov 27
0
Need Help with my Code for complex GARCH (GJR)
Hello,
i want to estimate a complex GARCH-model (see below).
http://r.789695.n4.nabble.com/file/n4112396/GJR_Garch.png
W stands for the Day of the Week Dummies. r stands for returns of stock
market indices. I stands for the GJR-term.
I need some help with three problems:
1.) implementation of the GJR-term in the variance equation
2.) compute robust covariance matrix
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
2005 Feb 01
0
GARCH, installing tserise package
Hi, there,
First of all, I am not familar with the GARCH concept as well as R interface.
I have three questions regarding GARCH (1,1).
First, I got tseries package from CRAN. Where exactly am I supposed to
install it?
In my case, I copies it to C:\Program Files\R\rw2001\library. What do
I need to do in order to actually install it?
Second, I am not sure if I've installed it properly, but
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
2003 Nov 27
2
would like to know how to simulated a GARCH(1,2)
Follow the example in tseries, we can simulated a GARCH(0,2),
n <- 1100
a <- c(0.1, 0.5, 0.2) # ARCH(2) coefficients
e <- rnorm(n)
x <- double(n)
x[1:2] <- rnorm(2, sd = sqrt(a[1]/(1.0-a[2]-a[3])))
for(i in 3:n) # Generate ARCH(2) process
{
x[i] <- e[i]*sqrt(a[1]+a[2]*x[i-1]^2+a[3]*x[i-2]^2)
}
x <- ts(x[101:1100])
and x is a GARCH(0,2).
But, I would like to know how
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 Nov 21
0
Expanding VaR package
Hi,
it would be nice if the VaR package could get expanded to work with
more models. I wrote a function which calculates the VaR for a
Garch(1,1) AR(2) model. Since I am fairly new to R I am sure it can be
written much neater.
If someone feels like having a go, here is what I have written
library(fSeries)
library(tseries)
VaR.Garch <- function(data,stockId=1,p=0.01,dt=1)
{
r <-
2008 Nov 22
1
Need some help in R programming code
Dear R guru,
I am Saikat Sarkar working as a researcher of Economics in Tampere
University, Finland. I am trying to estimate some Garch related tests with
Bayesian analysis by R programme.
I am not good in R but trying to survive.
Anyway I have the coding but not working properly. I have tried to find the
problem but failed. I am writing to all R gurus to help me out.
Could you please look at
2010 May 13
0
ARMA(1,1)-GARCH(1,1) rolling estimation question
Hi all,
I got the daily stock return data from 2005 - 2008, calculated from HF
minute data. (Thanks to Jeff and Josh).
Now, I set 05 - 07yr as the carlibration period for estimating the
parameters of ARMA(1,1)-GARCH(1,1) model, aqnd leave 08 for backtesting.
So I use the return data observations from 1:760 (yr 05-07) to estimate the
volatility on 2nd-Jan-08 (the position 761),
then use the
2007 Jun 16
1
fSeries - Ox - ver: 240.10068 - Steps to make it work
-Bugs and fixes reported to Diethelm Wuertz.
-In the interim. To make the Ox functions part of the fSeries package work please follow the following steps.
-------------------------------------------------
1. Install R-project.
2. Install fSeries.
3. Download: http://www.core.ucl.ac.be/~laurent/G@RCH/site/xbdcons/garch42.zip (G@RCH package for Ox)
4. Download:
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 =
2003 Jul 31
0
Trouble with optim
Dear All;
Searching on the achieve, many questions on optim() have been asked,
but I haven't seen the following.
The question began with my original inquiry on "Optimization failed
in fitting mixture 3-parameter Weibul l distribution using fitdistr()" which
I posted on Jul. 28, Prof. Ripley kindly advised me to look into options of
optim() for the answer. Following his advice and
2011 Feb 26
0
A problem about realized garch model
Hi, I am trying to write the Realized GARCH model with order (1,1)
The model can be describe bellow:
r_t = sqrt( h_t) * z_t
logh_t = w + b*logh_(t-1) + r*logx_(t-1)
logx_t = c + q*logh_t + t1*z_t +t2*(z_t ^2 -1) + u_t
and z follow N(0,1) , u follow N(0, sigma.u^2)
But I'm troubled with the simulation check for my code.
After I simulate data from the model and estimate the data,
I
2009 Mar 08
0
ARIMA second order differencing problem
Hi,
I have been using this site (
http://www.stat.pitt.edu/stoffer/tsa2/Rissues.htm) to help me with some
ARIMA modelling in R.
Unfortunately the methods mentioned do not appear to work with second order
differencing; arima(*, 2, *).
I have used some dummy data to illustrate my point.
When I use the xreg=... method, the estimate of intercept is *way* off. This
can be seen by the high s.e but I
2013 Mar 12
1
rugarch: GARCH with Johnson Su innovations
Hey,
I'm trying to implement a GARCH model with Johnson-Su innovations in order to simulate returns of financial asset. The model should look like this:
r_t = alpha + lambda*sqrt(h_t) + sqrt(h_t)*epsilon_t
h_t = alpha0 + alpha1*epsilon_(t-1)^2 + beta1 * h_(t-1).
Alpha refers to a risk-free return, lambda to the risk-premium.
I've implemented it like this:
#specification of the model
2009 Feb 13
1
need help with errors in betareg analysis
Hi
I'm trying to fit a model in betareg and I'm getting errors, but have no
idea what they mean or how to solve them. Does anyone have experience with
this?
> model <- betareg(ACT ~ ST*SoilT, data = actDL_F)
Warning messages:
1: In sqrt(W) : NaNs produced
2: In sqrt(W) : NaNs produced
3: In sqrt(1 + phihat) : NaNs produced
data summaries don't give any na's or problems I
2012 Apr 16
1
for help
Hi, we have a problem concerning the use and forecasting on the GARCH (1,
1) on financial data.
We would like to make predictions on future returns in a loop which moves
the window of estimation forward one unit for each iteration. Our code is
as follows:
> BJORN <- read.table("C:/Users/Osvald/Desktop/DATATILLUPPSATS.txt",
+ header=TRUE, sep="\t",