Displaying 20 results from an estimated 1000 matches similar to: "Multivariate chi-square distribution function"
2007 Nov 19
2
All nonnegative integer solution
Dear all,
Is there any method in R to find all possible nonnegative integer
solutions to the linear equation with unit coefficients as follow:
X1+X2+...+Xk=N
Thank you,
Amin Zollanvari
2003 Feb 16
1
multivariate sampling question again
Hi
Thanks for replying my question! What really interested me is that the
package providing some complex form sampling, such as wishart,
multinomial, dirichlet. And others for example conditional beta
distribution confining the random variable in the interval (a, b). Since
these concept are widely used in the baysian, I wonder whether somebody
has already written this package. Thanks!
Best
2005 Aug 03
1
multivariate F distribution
Dear List,
Is there any function in R to generate multivariate F distribution with
given correlation/covariance matrix?
Actually, I just want to generate some 2-dimentional non-normal data
sets (skewed) for low (may be around 0.3 cor coeff.) negatively and also
positively correlated variables ?
Thanks in advance.
Anna
2005 Feb 24
1
Density of the Multivariate T Distribution
Hi,
I am looking for an efficient way to compute the
values of the density function of a multivariate T
distribution - something like "dmvnorm", but for T
distr. Does this exist somewhere?
Many thanks,
Jan Bulla
Goettingen University
2007 Nov 28
0
trouble for building R package in Windows
Dear All,
I think I have followed everything for building my first R package
(Downloading Rtools, necessary files in necessary locations, no space
in path and...). But when in command Prompt I write "Rcmd check
mypackage" the first few steps are "OK" but then it gives the
following error:
checking whether package roots can be installed.....ERROR
installation failed
see
2012 Mar 01
1
Parameterization of Inverse Wishart distribution available in MCMCpack and bayesm libraries
Hello Everyone
Both the MCMCpack and the bayesm libraries allow us to make draws from the
Inverse Wishart distribution.
But I wanted to find out how exactly is the Inverse Wishart distribution
parameterized in these libraries.
The reason I ask is the following:
Now its generally standard to express Inverse Wishart as IW(0.5 * DOF,0.5*
Scale). (DOF-> Degree of freedom, Scale -> Scale
2012 Feb 05
1
Simulating from a Normal Inverted Wishart distribution
Hello everyone
I was wondering how would one simulate from a Normal Wishart Distribution
in R.
A normal inverted Wishart distribution is denoted by NIW (M,C,d,S), where
X/(Sigma) ~ N( M,C,(Sigma) ) -> a matrix normal distribution, (Sigma) ->
column dispersion matrix
(Sigma) ~ IW (d,S) -> inverted Wishart distribution
Thanks a lot !
Best
Shantanu
[[alternative HTML version
2003 Mar 31
2
Does R have an inverse wishart distribution?
If so, I''ve had trouble finding it. Can anyone help?
2005 Jul 26
1
Wishart Density
Dear R users,
I am doing MCMC using Metropolis-Hastings. My model is
bivariate-log-normal and the prior for variance-covariance is wishart
distribution. I am wondering if there are some simple codes about how
to get the density of Wishart distribution in my case ?
Thanks in advance.
Meihua
[[alternative HTML version deleted]]
2017 Oct 09
3
example of geom_contour() with function argument
Hi,
This is not a HW problem, sadly: I was last in a classroom 30 years ago,
and can no longer run off to the instructor :-(
I apologize but I cut and paste the wrong snippet earlier and made a typo
in doing so, but the result is the same with the more appropriate snippet.
require(mvtnorm)
require(ggplot2)
set.seed(1234)
xx <- data.frame(rmvt(100, df = c(13, 13)))
v <- ggplot(data = xx,
2017 Oct 09
0
example of geom_contour() with function argument
library(mvtnorm) # you were misusing "require"... only use require if
you plan to
library(ggplot2) # test the return value and fail gracefully when the
package is missing
set.seed( 1234 )
xx <- data.frame( rmvt( 100, df = c( 13, 13 ) ) )
xx2 <- expand.grid( X1 = seq( -5, 5, 0.1 ) # all combinations... could
be used to fill a matrix
, X2 = seq( -5, 5, 0.1 )
2010 Sep 06
1
sample a matrix with one element to be 1 from wishart distribution
Hi,
I am not sure if this make sense at all. I'd like to sample a matrix, which
follows a wishart / inverted wishart distribution. However, the (1,1)
element of this matrix should always be equal to 1. How can I handle it in
R? Any suggestion is greatly appreciated. Thanks a lot.
Sonia
[[alternative HTML version deleted]]
2005 Apr 28
1
riwish() problem
R users-
In moving from R 2.0.0 to R 2.1.0 in Windows, I have encountered a problem
with the "riwish" command in the package "MCMCpack". I've searched the
documentation and can't seem to figure it out. For example:
Define a matrix:
> lam <- matrix(c(.00233,-.00057,-.00057,.00190),2,2)
and then use the riwish command to generate a random inverse-Wishart
2009 Nov 21
3
python
Dear R users,
I would like to make my R code for MCMC faster. It is possible to integrate
C code into R but I think C is too complicated for me. I would need a C
introduction only for MCMC and I do not know if such a thing exists.
I was thinking of Python (and scipy). Where could I read about its
integration into R ? How developed are the statistical packages in Python ?
I could not find a
2017 Oct 09
2
example of geom_contour() with function argument
Hello Ulrik,
I apologize, but I can not see how to provide a pdf in place of the density
function which calculates a KDE (that is, something from the dataset in the
example). Can you please point to the specific example that might help?
Here is what I get:
require(mvtnorm)
require(ggplot2)
set.seed(1234)
xx <- data.frame(rmvt(100, df = c(13, 13)))
v <- ggplot(faithfuld, aes(waiting,
2010 May 10
2
Warning message
Hello,
I want to draw a histogram of the mean of sample observations drawn from multivariate t distribution. I am getting the following error corresponding to the code I used. Though I am getting the graph, but I am curious to know the warning message.
Warning messages:
1: In if (freq) x$counts else { :
the condition has length > 1 and only the first element will be used
2: In if (!freq)
2003 Feb 15
2
(no subject)
Hi,
Are there some packages which can generate multi-normal, multi-t, etc
multivariate sampling? thanks!
Best wishes,
Peng
*******************************
Peng Zhang
Department of Biostatistics
Harvard School of Public Health
655 Huntington Avenue
Boston, Massachusetts 02115
*******************************
I believe I can fly
I believe I can touch the sky
2017 Oct 09
2
example of geom_contour() with function argument
Can someone please point me to an example with geom_contour() that uses a
function? The help does not have an example of a function, and also I did
not find anything from online searches.
TIA,
BFD
-----------------------------------------------------------------------------------------------
How about geom_contour()?
Am So., 8. Okt. 2017, 20:52 schrieb Ranjan Maitra <maitra at
2017 Oct 09
0
example of geom_contour() with function argument
> On Oct 9, 2017, at 6:03 AM, Big Floppy Dog <bigfloppydog at gmail.com> wrote:
>
> Hello Ulrik,
>
> I apologize, but I can not see how to provide a pdf in place of the density
> function which calculates a KDE (that is, something from the dataset in the
> example). Can you please point to the specific example that might help?
>
> Here is what I get:
>
>
2004 Dec 16
1
help with multiple imputation using imp.mix
I am desperately trying to impute missing data using 'imp.mix' but always
run into this yucky error message to which I cannot find the solution. It's
the first time I am using mix and I'm trying really hard to understand, but
there's just this one step I don't get...perhaps someone knows the answer?
Thanks!
Jens
My code runs: