Displaying 20 results from an estimated 3000 matches similar to: "dmvnorm"
2006 Jan 20
2
big difference in estimate between dmvnorm and dnorm, how come?
Dear R community,
I was trying to estimate density at point zero of a multivariate
distribution (9 dimensions) and for this I was using a multinormal
approximation and the function dmvnorm , gtools package.
To have a sense of the error I tried to look the mismatch between a
unidimensional version of my distribution and estimate density at
point zero with function density, dmvnorm and dnorm.
At
2010 Mar 13
2
dmvnorm masked by emdbook
I am using curve3d in the emdbook package to graph a gaussian copula density
function generated via the copula package. Unfortunately, it appears that
emdbook masks dmvnorm from the package mvtnorm in a way that prohibits
copula from generating the gaussian copula. (Sounds very confusing!) For
example,
> library(copula)
> f<-function(x,y) dcopula(normalCopula(0),c(x,y))
>
2004 Oct 31
3
strange results with dmvnorm
I am experiencing strange results using dmvnorm. I define a scaled distance
matrix from the coordinates bellow and then calculate a covariance matrix using
a spherical correlation function. Then with certain combinations of
range and sill parameters dmvnorm is returning values greater than 1. Surely
the results of dmvnorm should be in the interval 0:1 (or do I just nead a
holiday?). In addition
2009 Nov 18
2
Error "system is computationally singular" by using function dmvnorm
Dear R users,
i try to use function dmvnorm(x, mean, sigma, log=FALSE)
from R package mvtnorm to calculate the probability of x
under the multivariate normal distribution with mean equal
to mean and covariance matrix sigma.
I become the following
Error in solve.default(cov, ...) :
system is computationally singular: reciprocal condition
number = 1.81093e-19
What could be the reason of it?
2007 Feb 26
3
returns from dnorm and dmvnorm
Hi All,
Why would calls to dnorm and dmvnorm return values that are above 1? For
example,
> dnorm(0.00003,mean=0, sd=0.1)
[1] 3.989423
This is happening on two different installations of R that I have.
Thank you.
Hailu
[[alternative HTML version deleted]]
2011 Aug 30
2
Multivariate Normal: Help wanted!
I have the following function, a MSE calc based on some Multivariate normals:
MV.MSE<-function(n,EP,X,S){
(dmvnorm(X,mean=rep(0,2),I+S+EP)-dmvnorm(X,mean=rep(0,2),I+S))^2
+
1/n*(dmvnorm(X,mean=rep(0,2),1+S+EP/2)*det(4*pi*EP)^-.5-
(dmvnorm(X,mean=rep(0,2),I+S+EP ))^2)}
I can get the MV.MSE for given values of the function e.g
2008 Mar 23
2
problem with 'install.packages'
Hi, All:
Is there a way to identify whether any users are using a
particular package in a shared network R installation?
I ask, because we have such a multiple-user installation and when
I tried to install a package using Rgui that was in use by Rterm on a
single-user installation, 'install.packages' deleted the existing
package but failed to install the new version;
2012 Apr 25
2
comparison of bivariate normal distributions
sorry for cross-posting
Dear all,
I have tow (several) bivariate distributions with a known mean and variance-covariance structure (hence a known density function) that I would like to compare in order to get an intersect that tells me something about "how different" these distributions are (as t-statistics for univariate distributions).
In order to visualize what I mean hear a little
2008 Oct 01
2
Bivariate normal
Package mvtnorm provides dmvnorm, pmvnorm that can be used to compute
Pr(X=x,Y=y) and Pr(X<x,Y<y) for a bivariate normal.
Are there functions that would compute Pr(X<x,Y=y)?
I'm currently using "integrate" with dmvnorm but it is too slow.
2010 Jun 23
3
integrate dmvtnorm
Hello, everyone,
I have a question about integration of product of two densities.
Here is the sample code; however the mean of first density is a function of
another random variable, which is to be integrated.
##
f=function(x) {dmvnorm(c(0.6, 0.8), mean=c(0.75, 0.75/x))*dnorm(x, mean=0.6,
sd=0.15)}
integrate(f, lower=-Inf, upper=Inf)
## error message
Error in dmvnorm(c(0.6, 0.8), mean = c(0.75,
2013 Jan 28
1
Adding 95% contours around scatterplot points with ggplot2
Hi all,
I have been looking for means of add a contour around some points in a
scatterplot as a means of representing the center of density for of the
data. I'm imagining something like a 95% confidence estimate drawn around
the data.
So far I have found some code for drawing polygons around the data. These
look nice, but in some cases the polygons are strongly influenced by
outlying points.
2009 Jun 22
1
The gradient of a multivariate normal density with respect to its parameters
Does anybody know of a function that implements the derivative (gradient) of
the multivariate normal density with respect to the *parameters*?
It?s easy enough to implement myself, but I?d like to avoid reinventing the
wheel (with some bugs) if possible. Here?s a simple example of the result
I?d like, using numerical differentiation:
library(mvtnorm)
library(numDeriv)
f=function(pars, xx, yy)
2001 Aug 30
1
MCMC coding problem
Dear All,
I am trying to convert some S-plus code that I have to run MCMC into
R-code. The program works in S-plus, but runs slowly.
I have managed to source the program into R. R recognizes that the program
is there; for example, it will display the code when I type the function
name at the prompt. However, the program will not run. When I try to run
the program, I get the following error
2008 Aug 01
2
contour lines in windows device but neither in pdf nor in postscript
library(mvtnorm)
x = seq(-4,4,length=201)
xy = expand.grid(x,x)
sigma = (diag(c(1,1))+1)/2
d2 = matrix(dmvnorm(xy,sigma=sigma),201)
xsamp = rmvnorm(200,sigma=sigma)
contour(x,x,d2)
points(xsamp,col=3,pch=16)
pdf("pdftry.pdf")
contour(x,x,d2)
points(xsamp,col=3,pch=16)
dev.off()
postscript("pstry.ps")
contour(x,x,d2)
points(xsamp,col=3,pch=16)
dev.off()
# I can see
2020 Jun 04
2
mclust package installation is preparing for lazy loading and never finishes
Hi,
After loading R 4.0.0 on Ubuntu 20.04.
R version 4.0.0 (2020-04-24) -- "Arbor Day"
Copyright (C) 2020 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()'
2002 Jul 09
1
RE: mvtnorm package installation failure
Hi,
Thank you for the tip.
I tried to re-intall R from Debian "stable", in which R's version is 1.4.0. And the installation
of "mvtnorm" works.
I then re-installed R yet again from Debian "unstable" (woody), in which R's version is 1.5.1.
The installation of "mvtnorm" fails again with the same error message. Another package that
failed with the
2002 Nov 12
1
Probabilities for bivariate normal distribution with adapt
Dear R-List:
I`m trying to calculate the probabilities for a bivariate normal
distribution while using the mvtnorm-package(dmvnorm) and the
adapt-package for multidimensional integration.
The problem is that I can`t specify the upper bound in the adapt-package
the way I need it because I don`t need a rectangular area. I want to
calculate the probability starting at the origin under the line y=x.
2011 May 12
2
Exporting interactive 3D plots with axes and labels
Hi,
I have a question about exporting interactive 3D plots. I use the following code to plot a contour of a trivariate normal distribution:
library(mvtnorm)
library(rgl)
library(misc3d)
n=25
x=seq(-3,3,length=n)
X=cbind(rep(x,each=n**2),rep(rep(x,each=n),n),rep(x,n**2))
p=array(dmvnorm(X,sigma=diag(3)*0.5+0.5),c(n,n,n))
contour3d(p,x,x,x,level=mean(p))
lim=c(-3,3)
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
2006 Feb 15
1
S3 generics without NS and cleanEx()
Good morning,
we recently observed a problem with importing S3 generics from a foreign
package (without namespace), defining a S3 method in a package _with_
namespace and the `cleanEx()' function which is automatically generated
and executed before examples are run by R CMD check.
To be more precise. Package `strucchange' defines a S3 generic
sctest <- function(x, ...)