Displaying 20 results from an estimated 3000 matches similar to: "About the Skew Student distribution"
2006 Jul 11
4
Date Format
Hi everybody,
I need your precious help for, I think, a simple request, but I do not manage to solve this.
When I use a "table" function with dates in the rows, the rows are coerced to number after the table function.
So I need to transform the row names into date format. But I do not manage.
Therefore, for an example, I manage to write this :
datetest<-"06/01/2001"
2006 Jul 11
4
Date Format
Hi everybody,
I need your precious help for, I think, a simple request, but I do not manage to solve this.
When I use a "table" function with dates in the rows, the rows are coerced to number after the table function.
So I need to transform the row names into date format. But I do not manage.
Therefore, for an example, I manage to write this :
datetest<-"06/01/2001"
2007 Mar 01
1
Fit Student Copula
Hello everybody,
I have a big problem that I do not manage to solve !
I will be very grateful if you can solve this !
I want to fit a t Copula with the copula package :
> student.cop <- ellipCopula("t", param = c(0.5, 0.6, 0.7), dim = 3, dispstr = "un",df=5)
> x<-rcopula(student.cop,1000)
> fit <- fitCopula(x, student.cop, c(0.5,0.5,0.5,5))
And there is an
2005 Sep 01
5
Multivariate Skew Normal distribution
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch
> [mailto:r-help-bounces at stat.math.ethz.ch]On Behalf Of Caio Lucidius
> Naberezny Azevedo
> Sent: 01 September 2005 12:09
> To: Help mailing list - R
> Subject: [R] Multivariate Skew Normal distribution
>
>
> Hi all,
>
> Could anyone tell me if there is any package (or function)
2009 Jul 06
1
transform multi skew-t to uniform distribution
Hi R-users,
I have a data from multi skew t and would like to transform each of the data to uniform data. I tried using 'pmst' but only got one output:
> rr1 <- as.vector(r1);rr1
[1] 0.7207582 5.2250906 1.7422237 0.5677233 0.7473555 -0.6020626 -2.1947872 -1.1128313 -0.6587316 -1.1409261
> pmst(rr1, xi=rep(0,10), Omega=diag(10), alpha=rep(1,10), df=5)
[1] 3.676525e-09
2010 Mar 01
1
Have another apparent version skew
The package "sm" was obtained twice, one using R's built-in updating of
packages, the second directly. In both cases the USA-NC CRAN mirror was
used. In both cases, loading the package under R 2.10.1 for Windows
resulted in a 'package obsolete' kind of message. Switching the mirror
to USA-CA-1 (Berkeley) got a good package that loaded without complaint.
R version 2.10.1
2008 Feb 28
2
EMM: how to make forecast using EMM methods?
Hi all,
We followed some books and sample codes and did some EMM estimation,
only to find it won't be able to generate forecast.
This is because in the stochastic volatility models we are estimating,
the volatilities are latent variables, and we want to forecast 1-step
ahead or h-step ahead volatilities.
So it is nice to have the system estimated, but we couldn't get it to
forecast at
2008 Feb 07
2
where do I find stochastic volatilities models in R or Matlab?
Hi all,
Does anybody have the source code of stochastic volatility models in R
or Matlab, for example, the Bayesian based or the simulation based SV
estimations as described by Prof Eric Zivot in the following
discussion?
https://stat.ethz.ch/pipermail/r-sig-finance/2005q4/000501.html
--------------
I am wondering what is the current status of estimating stochastic vol
models and what's
2007 Oct 23
1
multivariate Stochastic Volatility and GARCH
Dear everyone,
i`m a german economics student, writing my master´s thesis about
"Multivariate Volatility Models". After having read about theoretical
aspects of Multivariate GARCH ans Stochastic Volatility Models, I would like
to compare DCC-GARCH and DC-SV with help of an empirical application. I
figuered out that one has to use MCMC-simulation-methods for that. Some days
ago I
2004 Apr 08
1
plot help
Hie!
I do not manage to make several plots on a same graph ( for example two
densities on the same graph )
thanks for the answer
Pierre Clauss
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2006 Aug 10
0
sn package - skew t - code for analytical expressions for first 4 moments
hello users of the SN package,
i thought i post here some useful help on R code on the 4 moments for the skew t
sampling gives seldom good results for skewness and kurtosis, so
one really needs the analytical results,
it took me some time to get it from the article
Azzalini, A. & Capitanio, A. (2003),
Distributions generated by perturbation of symmetry with emphasis on
a multivariate
2011 Jul 02
1
Simulating inhomogeneous Poisson process without loop
Dear all
I want to simulate a stochastic jump variance process where N is Bernoulli
with intensity lambda0 + lambda1*Vt. lambda0 is constant and lambda1 can be
interpreted as a regression coefficient on the current variance level Vt. J
is a scaling factor
How can I rewrite this avoiding the loop structure which is very
time-consuming for long simulations?
for (i in 1:N){
...
N <- rbinom(n=1,
2011 Aug 03
1
the significance of BEKK estimation
Dear ALL,
I use BEKK package to estimate Bivariate GARCH model. But when the results
come out, there's no t-stat or p-value of the estimated coeffients. Does
anyone know how to get the significance?
Followings are the codes I input,
>P1=data.frame(x,y)
>y1=mvBEKK.est(P1)
>mvBEKK.diag(y1)
Anyhelp would be appreciated!
Sincere,
Zoe
--
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2008 Dec 11
2
how to get the CDF of a density() estimation?
Hi,
I've estimated a simple kernel density of a univariate variable with
density(), but after I would like to find out the CDF at specific
values.
How can I do it?
thanks for your help, with it I am very close to finish my first
little bit more serious work in R,
Viktor
2003 Apr 24
5
Fast R implementation of Gini mean difference
I have written the following function to calculate the weighted mean
difference for univariate data (see
http://www.xycoon.com/gini_mean_difference.htm for a related
formula). Unsurprisingly, the function is slow (compared to sd or mad)
for long vectors. I wonder if there's a way to make the function
faster, short of creating an external C function. Thanks very much
for your advice.
gmd
2008 Oct 14
0
Fwd: sn package - skew t - code for analytical expressions for first 4 moments
Hello
please note that the code at
https://stat.ethz.ch/pipermail/r-help/2006-August/110892.html
to compute indices of skewness and kurtosis for the skew-t
distribution is not correct.
It has been kindly pointed out that i made some error in this code,
which was a bit too quickly copied from the paper.
The 'sn' package already contains a facility for computing
the cumulants, namely
2013 Aug 26
0
Bivariate skew normal cdf; very slow
Dear all,
I am calculating the bivariate skew normal cdf in "sn" package using "pmsn" function.
Although it is quite convenient ( thanks to prof. Azzalini) but it seems to be slow.
For example, it takes about 1 minute in calculation of 100k of such cdf values.
I am thinking to write a c++ code for this although not very familiar with it.
Any other idea?
Thanks in advance,
2012 Dec 08
0
Modelling a skew-normal distribution using glm/ mgcv
Hello,
Suppose my variable,S, (time for something to start) is a skew-normal
distribution [1]. Can glm and mgcv handle this type of distribution for the
dependent variable?
Regards
Saptarshi
[1] http://azzalini.stat.unipd.it/SN/
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2003 May 20
4
Output to connections
In the document "R Data Import/Export", section "Output to connections",
there is the following portion of code:
## convert decimal point to comma in output, using a pipe (Unix)
zz <- pipe(paste("sed s/\\./,/ >", "outfile"), "w")
cat(format(round(rnorm(100), 4)), sep = "\n", file = zz)
close(zz)
## now look at the output
2003 May 13
2
RMySQL crashes R
I have justed upgraded R v1.7.0 on Windows NT 4 and have installed the
latest RMySQL (version 0.5-1)and DBI (version 0.1-5) packages.
When I issue the following commands (tactfully adjusted) R just crashes and
disappears, any ideas?
require(RMySQL)
m <- dbDriver("MySQL")
con <- dbConnect(m, dbname="xxx", user="xxx", password="xxx",