Re: [R] R error: system is computationally singular when building GMM model

2013-01-13 Thread Uwe Ligges
On 13.01.2013 15:08, zoe chan wrote: Dear, I built the generalized method of moments model to estimate the sales rank in the bookstore using plm package in R. The equation is: data1.gmm <- pgmm(dynformula(lnsales_rank ~ ln_price + avg_ham_rate + avg_spam_rate + num_of_ham+ num_of_spam + ship

[R] R error: system is computationally singular when building GMM model

2013-01-13 Thread zoe chan
Dear, I built the generalized method of moments model to estimate the sales rank in the bookstore using plm package in R. The equation is: data1.gmm <- pgmm(dynformula(lnsales_rank ~ ln_price + avg_ham_rate + avg_spam_rate + num_of_ham+ num_of_spam + ship_code2 +ship_code3 +ship_code4+ ship_co

Re: [R] R Error: System is computationally singular

2012-05-24 Thread Nathan Svoboda
; r-help@r-project.org Subject: Re: [R] R Error: System is computationally singular Nathan, This does help, as in the first cut you provided, there was no variability in LOCS for LCOVER >= 5 and you have very few values of LOCS > 0 (you still do, relative to the scale of the total). Ha

Re: [R] R Error: System is computationally singular

2012-05-24 Thread David Winsemius
On May 24, 2012, at 3:41 PM, Nathan Svoboda wrote: Re: [R] R Error: System is computationally singular Hi David, My apologies, I am not sure if this makes a big difference in your assessment of the problem, but the results I just sent were only from a portion (1/15) of the data. The

Re: [R] R Error: System is computationally singular

2012-05-24 Thread Marc Schwartz
Nathan, This does help, as in the first cut you provided, there was no variability in LOCS for LCOVER >= 5 and you have very few values of LOCS > 0 (you still do, relative to the scale of the total). Have you tried using a zero inflated negative binomial model (dist = "negbin") rather than poi

Re: [R] R Error: System is computationally singular

2012-05-24 Thread Nathan Svoboda
, Nate Nathan Svoboda Graduate Research Assistant Mississippi State University From: David Winsemius [mailto:dwinsem...@comcast.net] Sent: Thu 5/24/2012 1:54 PM To: Nathan Svoboda Cc: r-help@r-project.org Subject: Re: [R] R Error: System is computationally

Re: [R] R Error: System is computationally singular

2012-05-24 Thread Nathan Svoboda
Thank you for your quick reply, When I run the code you provide I get this output: LCOVER LOCS 1 2 3 4 5 6 7 9 0 214507 79939 69803 778359 22932 32391 99630 8082 1 15 7 1 32 0 0 0 0 2 2 1

Re: [R] R Error: System is computationally singular

2012-05-24 Thread Nathan Svoboda
: System is computationally singular On May 24, 2012, at 1:57 PM, Nathan Svoboda wrote: > Greetings, > > I am trying to fit a zero-inflated Poisson model using zeroinfl() > from the > pscl library. I have 5 covariates (4 continuous, 1 categorical); the > categorical variabl

Re: [R] R Error: System is computationally singular

2012-05-24 Thread David Winsemius
On May 24, 2012, at 1:57 PM, Nathan Svoboda wrote: Greetings, I am trying to fit a zero-inflated Poisson model using zeroinfl() from the pscl library. I have 5 covariates (4 continuous, 1 categorical); the categorical variable has 7 levels. I have had success fitting models that contain

[R] R Error: System is computationally singular

2012-05-24 Thread Nathan Svoboda
Greetings, I am trying to fit a zero-inflated Poisson model using zeroinfl() from the pscl library. I have 5 covariates (4 continuous, 1 categorical); the categorical variable has 7 levels. I have had success fitting models that contain only the continuous covariates; however, when I add the cate