similar to: Cholesky update/downdate

I have been playing around with sparse matrices in the Matrix package, in particularly with the Cholesky factorization of matrices of class dsCMatrix. And BTW, what a fantastic package. My problem is that I have to carry out repeated Cholesky factorization of a spares symmetric matrices, say Q_1, Q_2, ...,Q_n, where the Q's have the same non-zero pattern. I know in this case one does

Hello, I have been attempting to run a poisson glmm using lme4 for some time now and have had a lot of trouble. I would say 9 times out of 10 I receive the following warning: CHOLMOD warning: %h Error in mer_finalize(ans) : Cholmod error `not positive definite' at file:../Cholesky/t_cholmod_rowfac.c, line 432 My data are counts of microbe colony forming units (CFUs) collected from

I figured most of it out. The Spec::Rails stuff was something in the code which has been fixed by revision 3099. The test methods partially make sense. Since the test/unit code has been integrated, methods with test in them are automatically turned into specs. However, the test? method is in a lib file that isn''t directly loaded into the specs. It is a convenience method: def

We have a custom implementation of the Mother Object idea. It''s inside of a module, basically like this: module Factory %w(account friendship person invitation message asset email_address birth).each do |klass| eval <<-EOF def self.create_#{klass}(attributes = {}) default_attributes = valid_#{klass}_attributes #{klass.camelize}.create!

This is a Request For Comment, also BCCed to 390 package maintainers of reverse dependencies of the Matrix package. Most users and package authors working with our 'Matrix' package will be using it for numerical computations, and so will be using "dMatrix" (d : double precision) matrix objects M, and indirectly, e.g., for M >= c will also use "lMatrix" (l:

Can we do Cholesky Decompositon in R for any matrix --------------------------------- [[alternative HTML version deleted]]

Hi everyone: I try to use r to do the Cholesky Decomposition,which is A=LDL',so far I only found how to decomposite A in to LL' by using chol(A),the function Cholesky(A) doesnt work,any one know other command to decomposte A in to LDL' My r code is: library(Matrix) A=matrix(c(1,1,1,1,5,5,1,5,14),nrow=3) > chol(A) [,1] [,2] [,3] [1,] 1 1 1 [2,] 0 2 2

Dear fellow R Users: I am doing a Cholesky decomposition on a correlation matrix and get error message the matrix is not semi-definite. Does anyone know: 1- a work around to this issue? 2- Is there any approach to try and figure out what vector might be co-linear with another in thr Matrix? 3- any way to perturb the data to work around this? Thanks for any suggestions.

Hi, I am new to this list. I have a question regarding including both spatial and temporal random factors in lmer. These two are not nested, and an example of model I try to fit is model1<-lmer(Richness~Y+Canopy+Veg_cm+Treatment+(1|Site/Block/Plot)+(1|Year), family=poisson, REML=FALSE), where richness = integer Y & Treatment = factor Canopy & Veg_cm = numerical, continous

Dear R-Users I used the nlme library to fit a linear mixed model (lme). The random effect standard errors and correlation reported are based on a Log-Cholesky parametrization. Can anyone tell me how to get the Covariance matrix of the random effects, given the above mentioned parameters based on the Log-Cholesky parametrization?? Thanks in advance Pryseley

Hello Everyone I have a MCMC loop to calculate a time varying hierarchical Bayesian structure. This requires me to use around 5-6 matrix inversions in the loop. I use cholesky and chol2inv for the matrix decomposition. Because of the data I am working with I am required to invert a 167 by 167 matrix twice in one iteration. I need to run the iteration for 10000 times, but I get the error

What''s the status on a rake task for the story runner. If nothing is in progress, where could I start to try and build one? JD

Hi R usrs, I want to build R-2.10.0 on HP-UX, but I got following error message: ld: Unsatisfied symbol "zgemm" in file CHOLMOD.a[cholmod_l_super_numeric.o] ld: Unsatisfied symbol "zgemv" in file CHOLMOD.a[cholmod_l_super_solve.o] ld: Unsatisfied symbol "zherk" in file CHOLMOD.a[cholmod_l_super_numeric.o] ld: Unsatisfied symbol "ztrsm" in file

Hi R-help citizens, I'm having trouble making version 0.99-6 of Matrix on FreeBSD 6.0. The error message is: * Installing *source* package 'Matrix' ... ** libs gcc -I/usr/local/lib/R/include -I/usr/local/include -D__NO_MATH_INLINES -fPIC -g -O2 -c Csparse.c -o Csparse.o ... numerous lines deleted ... gcc -I/usr/local/lib/R/include -I/usr/local/include -D__NO_MATH_INLINES

How do I use the ruby debugger with a specific test (not the whole spec file)? I want to do something like this. $ rdebug spec/models/user_spec.rb -s "should error if not new_record" ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search.

Hi, Having just played with getting my first plain text story working, I like how it all fits together. It worked out nicely. However, I don''t feel our project needs to have stories as plain text, in fact it''s a slight hindrance for us. Is there any sensible mechanism for doing integration testing using rspec without plain text stories? Thanks, Rob

Hi there, Given a positive definite symmetric matrix, I can use chol(x) to obtain U where U is upper triangular and x=U'U. For example, x=matrix(c(5,1,2,1,3,1,2,1,4),3,3) U=chol(x) U # [,1] [,2] [,3] #[1,] 2.236068 0.4472136 0.8944272 #[2,] 0.000000 1.6733201 0.3585686 #[3,] 0.000000 0.0000000 1.7525492 t(U)%*%U # this is exactly x Does anyone know how to obtain L such

Dear All, My question is simple but I need someone to help me out. Suppose I have a positive definite matrix A. The funtion chol() gives matrix L, such that A = L'L. The inverse of A, say A.inv, is also positive definite and can be factorized as A.inv = M'M. Then A = inverse of (A.inv) = inverse of (M'M) = (inverse of M) %*% (inverse of M)' = ((inverse of

Hi, I am getting a warning message when I am fitting a generalized linear mixed model (m1.2 below). CHOLMOD warning: matrix not positive definite Error in objective(.par, ...) : Cholmod error `matrix not positive definite' at file:../Supernodal/t_cholmod_super_numeric.c, line 614 Any idea? Thanks for your help, Reza > sessionInfo() R version 2.4.1 (2006-12-18) i386-pc-mingw32

Hi all, I have trouble to compile Matrix packages on Solar10 x86-64 with Sun compilers. I saw some postings on this but am not sure how to solve this problem. It is becoming critical as I cannot install biocLite() because of its dependency on Matrix. Could you direct me how to resolve the issue? Thanks in advance! Dongseok R version 2.8.1 (2008-12-22) Copyright (C) 2008 The R Foundation for