Displaying 20 results from an estimated 3000 matches similar to: "Error "system is computationally singular" by using function dmvnorm"
2010 Jan 05
2
Align two protein sequences using BLAST
Dear R users,
I would like to align two protein sequences using BLAST
(bl2seq). The question is whether this programm have been
implemented in R.
Thank you for your help,
Alla.
2013 Jun 06
1
dmvnorm
Summary:
+ I am writing an R extension that needs to call dmvnorm more than
10,000 times during a model fitting computation.
+ My extension uses openmp for parallel execution.
+ As of R 3.0, it is no longer permitted for threads to call the R
interpreter because there is a stack overflow check that always trips
because the thread's stack is different from what R is expecting.
+
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 25
1
tick marks on fold change versus fold change plot
Dear R users,
i try to produce the fold change versus fold change plot
where i have the values for x and y ranging from 0.01 to
100. So i start with
plot(x,y,xlim=c(0.01,100),ylim=c(0.01,100), axes=F).
Then i would like both axes to have tick marks as
c(0.01,0.1,1,10,100) but they should appear equidistant.
How should i manage this?
Thank you for your help,
Alla.
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
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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,
2010 Mar 18
1
Unable to install Cairo package
Dear R users,
I'm running R version 2.10.1.
I tried installing the Cairo package and I got the
following message:
* installing *source* package ?Cairo? ...
checking for gcc... gcc -std=gnu99
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables...
checking for
2006 Nov 07
4
solve computationally singular
Hi uRsers,
when inverting a 2 by 2 matrix using solve, I encountered a error message:
solve.default(sigma, tol = 1e-07) :
system is computationally singular: reciprocal condition number
= 1.7671e-017
and then I test the determinant of this matrix: 6.341393e-06.
In my program, I have a condition block that whether a matrix is
invertible like this:
if(det(sigma)<1e-7) return NULL;
2012 Oct 25
5
system is computationally singular: reciprocal condition number
Hi folks,
I know, this is a fairly common question and I am really disappointed that I
could not find a solution.
I am trying to calculate Mahanalobis distances in a data frame, where I have
several hundreds groups and several hundreds of variables.
Whatever I do, however I subset it I get the "system is computationally
singular: reciprocal condition number" error.
I know what it means
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)
2009 Jun 25
2
Error: system is computationally singular: reciprocal condition number
I get this error while computing partial correlation.
*Error in solve.default(Szz) :
system is computationally singular: reciprocal condition number =
4.90109e-18*
Why is it?Can anyone give me some idea ,how do i get rid it it?
This is the function i use for calculating partial correlation.
pcor.mat <- function(x,y,z,method="p",na.rm=T){
x <- c(x)
y <- c(y)
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.
2004 Dec 09
1
System is computationally singular?
Hi all,
I was using the Newton-Raphson method to estimate paremeters in the model developed by my supervisor. However, when I interatively computed theta(t+1)=theta(t) - solve(H)*s (where the Hessian matrix and score vector were explicitely derived), I got the error message: Error in solve.default(H) : system is computationally singular: reciprocal condition number = 1.70568e-032. Assume my score
2005 Aug 08
2
computationally singular
Hi,
I have a dataset which has around 138 variables and 30,000 cases. I am
trying to calculate a mahalanobis distance matrix for them and my
procedure is like this:
Suppose my data is stored in mymatrix
> S<-cov(mymatrix) # this is fine
> D<-sapply(1:nrow(mymatrix), function(i) mahalanobis(mymatrix, mymatrix[i,], S))
Error in solve.default(cov, ...) : system is computationally