Displaying 20 results from an estimated 9000 matches similar to: "multivariate simulation"
2009 May 18
2
Simulation from a multivariate normal distribution
I must to create an array with dimensions 120x8x500. Better I have to make 500 simulations of 8 series of return from a multivariate
normal distribution. there's the command "mvrnorm" but how I can do this repeating the simulation 500 times?"
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2008 May 09
1
Multivariate simulation
Dear everyone, I am having problem simulating multivariate data. Though I was able to simulate the data, but finding the variance-covariance matrix of simulated data did not give exact covariance matrix used in simulating the data. Unlike some other packages, like stata, using command "corr2data" will simulate data having the covariance matrix exactly with the specified covariance
2012 Oct 12
1
better example for multivariate data simulation question-please help if you can
Dear?All,
?
a few weeks ago I have posted a question on the R help listserv that?some of you have responded to with a great solution, would like to thank you for that? again.?I thought I would reach out to you with the issue I am trying to solve now. I have posted the question a few days ago, but probably it was not?clear enough, so I thought i try it again.?At times I have a multivariate example
2004 Jun 25
2
Simulating from a Multivariate Normal Distribution Using a Correlation Matrix
Hello,
I would like to simulate randomly from a multivariate normal distribution using a correlation
matrix, rho. I do not have sigma. I have searched the help archive and the R documentation as
well as doing a standard google search. What I have seen is that one can either use rmvnorm in
the package: mvtnorm or mvrnorm in the package: MASS. I believe I read somewhere that the latter
was
2012 Jun 15
2
Multivariate Normal and loops
Hi,
i'm not english and i'm not very familiar to R, and i'm asking if you can
help me.
I'm wondering how to create a multivariate normal an then repeat this for a
sample of T=1000, and the save this result.
Thank you very much for your helping
--
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2007 Aug 13
1
simulate data from multivariate normal with pre-specified correlation matrix
For example, the correlation matrix is 3x3 and looks like
1 0.75 0 0 0
0.75 1 0 0 0
0 0 0 0 0
Can I write the code like this?
p<- 3 # number of variables per observation
N<- 10 # number of samples
# define population correlation matrix sigma
sigma<-matrix(0,p,p) #creates a px p matrix of 0
rank<-2
for (i in 1:rank){
for (j in 1:rank){
rho<-0.75
2007 Nov 16
1
generate multivariate F with specified correlation matrix
Dear all,
In MATLAB, to generate multivariate F with specified correlation matrix Pn I can use the code such as
Z = mvnrnd([0 0 0 0 0], Pn, N);
U = normcdf(Z,0,1);
X = [finv(U(:,1),5,15) finv(U(:,2),5,15) finv(U(:,3),5,15) finv(U(:,4),5,15) finv(U(:,5),5,15)];
Is there something similar in R?
Thank you for your time.
2005 May 03
1
multivariate Shapiro Wilks test
Hello,
I have a question about multivariate Shapiro-Wilks test.
I tried to analyze if the data I have are multivariate normal, or how
far they are from being
multivariate normal. However, any time I did
>mshapiro.test(mydata)
I get the message:
Error in solve.default(R %*% t(R), tol = 1e-18) :
system is computationally singular: reciprocal condition number
= 5.38814e-021
I tried
2007 May 10
1
Re : CDF of a Multivariate Normal
Hello,
In my simulations, I have to use the values of the cumulative distribution function of a multivariate normal with known mean vector and dispersion matrix. Please, can you tell me if there is a package in R to do that?
Thank you very much for your greatly appreciate cooperation.
Bernard Colin
Colin Bernard
Professeur titulaire
Département de Mathématiques
Faculté des Sciences
Université
2002 Dec 04
1
Mixture of Multivariate Gaussian Sample Data
Hey, I am confused about how to generate the sample data from a mixture of
Multivariate Gaussian ditribution.
For example, there are 2 component Gaussian with prior
probability of 0.4 and 0.6,
the means and variances are
u1=[1 1]', Cov1=[1 0;0 1]
and
u2=[-1 -1]', Cov2=[1 0;0 1]
repectively.
So how can I generate a sample of 500 data from the above mixture
distribution?
Thanks.
Fred
2008 Dec 08
1
Multivariate kernel density estimation
I would like to estimate a 95% highest density area for a multivariate
parameter space (In the context of anova). Unfortunately I have only
experience with univariate kernel density estimation, which is remarkebly
easier :)
Using Gibbs, i have sampled from a posterior distirbution of an Anova model
with k means (mu) and 1 common residual variance (s2). The means are
independent of eachother, but
2010 Jun 17
1
simulating data from a multivariate dist
Sir,
I am working on fitting distribution on multivariate financial data and then
simulate observations from that fitted distribution. I use stepAIC.ghyp()
function of 'ghyp' library which select the best fitted distribution from
generalized hyperbolic distribution class on the given dataset.
data(indices)
# Multivariate case:
aic.mv <- stepAIC.ghyp(indices, dist =
2003 Sep 30
2
truncated multivariate normal
Please,
I would like to know how to generate a truncated multivariate normal
distribution k - dimensional, X ~ NT(mu, Sigma), where the
elements of X to be non-negative (except the first), and the first
dimension is strictly larger than zero.
Example:
X ~ NT_2(mu, Sigma),
where mu=c(0.5, 0.5) and Sigma=c([120, 191], [191,154]), with X_1>0
and X_2>=0
Could anybody help
2010 Aug 24
3
generate random numbers from a multivariate distribution with specified correlation matrix
Hi all,
rmvnorm()can be used to generate the random numbers from a multivariate
normal distribution with specified means and covariance matrix, but i want
to specify the correlation matrix instead of covariance matrix for the
multivariate
normal distribution.
Does anybody know how to generate the random numbers from a multivariate
normal distribution with specified correlation matrix? What about
2010 Nov 03
2
multivariate Poisson distribution
Hello, from a search of the archives and functions, I am looking for information on creating random correlated counts from a multivariate Poisson distribution. I can not seem to find a function that does this. Perhaps, it has not yet been created. Has anyone created an R package that does this.
thanks,
Jourdan Gold
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2008 Mar 05
1
Need help for calculating cross-correlation between 4 multivariate time series data
Hi all,
I would like to know whether there is any function in R were i can
find the cross-correlation of two or more multivariate (time series) data. I
tried the function ccf() but it seems like to have two univariate datasets.
Please let me know.
sincerely,
sandeep
--
Sandeep Joseph PhD
Post Doctoral Associate
Center for Tropical & Emerging Global Diseases
Paul D. Coverdell Center,
2003 May 06
4
Questons about R capabilities
Hello,
1) I am interested in performing a limited-dependent variable linear regression. By this I mean a classical linear regression, but for the case where the values of the dependent variable cannot vary from -infinity to +infinity, but are truncated and so are between two finite limits L1 and L2. Does R1.7 have this capability? If so what is (are) the relevant command(s)?
2) I am also
2008 Jun 26
2
constructing arbitrary (positive definite) covariance matrix
Dear list,
I am trying to use the 'mvrnorm' function from the MASS package for
simulating multivariate Gaussian data with given covariance matrix.
The diagonal elements of my covariance matrix should be the same,
i.e., all variables have the same marginal variance. Also all
correlations between all pair of variables should be identical, but
could be any value in [-1,1]. The problem I am
2011 Jan 22
1
faster mvrnorm alternative
Hello,
does anybody know another faster function for random multivariate normal
variable simulation? I'm using mvrnorm, but as profiling shows, my algorithm
spends approximately 50 % in executing mvrnorm function.
Maybe some of you knows much faster function for multivariate normal
simulation?
I would be very gratefull for advices.
--
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2011 Feb 08
1
Simulation of Multivariate Fractional Gaussian Noise and Fractional Brownian Motion
Dear R Helpers,
I have searched for any R package or code for simulating multivariate
fractional Brownian motion (mFBM) or multivariate fractional Gaussian noise
(mFGN) when a covariance matrix are given. Unfortunately, I could not find
such a package or code.
Can you suggest any solution for multivariate FBM and FGN simulation? Thank
you for your help.
Best Regards,
Ryan
-----
Wonsang You