Monica Palaseanu-Lovejoy
2004-Apr-23 09:45 UTC
[R] GepR - bayesian modelling - please help!
Hi, I am coming back with a question about GeoR hopping somebody can help. I am doing a bayesian kriging and the prediction coordinates are shifted 0.1 m from the data coordinates. I am using the following command and i am getting the following error: zn.bayes <- krige.bayes(zn.gdata, loc = loc1, model = model.control(cov.model = "exponential", lambda = 0), prior = prior.control(phi.prior ="exponential", phi = 89.1948), output=output.control(n.predictive=2, mean.var = TRUE, quantile = c(0.025, 0.25, 0.5, 0.75, 0.975), threshold = c(300))) Error: Error in cond.sim(env.loc = base.env, env.iter = iter.env, loc.coincide = get("loc.coincide", : chol: matrix not pos def, diag[13]= -3.487549e-019 What i am doing wrong? The location loc1 is a data frame with the shifted coord. values. Any suggestion is very well appreciated. Thanks, Monica
Paulo Justiniano Ribeiro Jr
2004-Apr-23 15:49 UTC
[R] GepR - bayesian modelling - please help!
Monica Could you please send me the zn.gdata and loc1 objects and I will investigate this P.J. On Fri, 23 Apr 2004, Monica Palaseanu-Lovejoy wrote:> Hi, > > I am coming back with a question about GeoR hopping somebody > can help. > > I am doing a bayesian kriging and the prediction coordinates are > shifted 0.1 m from the data coordinates. > > I am using the following command and i am getting the following > error: > > zn.bayes <- krige.bayes(zn.gdata, loc = loc1, model > model.control(cov.model = "exponential", lambda = 0), > prior = prior.control(phi.prior ="exponential", phi > 89.1948), output=output.control(n.predictive=2, > mean.var = TRUE, quantile = c(0.025, 0.25, 0.5, 0.75, > 0.975), threshold = c(300))) > > Error: Error in cond.sim(env.loc = base.env, env.iter = iter.env, > loc.coincide = get("loc.coincide", : > chol: matrix not pos def, diag[13]= -3.487549e-019 > > What i am doing wrong? The location loc1 is a data frame with the > shifted coord. values. Any suggestion is very well appreciated. > > Thanks, > > Monica > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > >Paulo Justiniano Ribeiro Jr Departamento de Estat??stica Universidade Federal do Paran?? Caixa Postal 19.081 CEP 81.531-990 Curitiba, PR - Brasil Tel: (+55) 41 361 3471 Fax: (+55) 41 361 3141 e-mail: pj at est.ufpr.br http://www.est.ufpr.br/~paulojus
Monica Palaseanu-Lovejoy
2004-Apr-23 16:49 UTC
[R] GepR - bayesian modelling - please help! Corrections ....
Hi again, I was checking again everything after i sent you my data. It seems that the problem is the following. My prediction locations are different in number than my data locations ..... i forgot that when i built the geodata object few points had more than one value so i used the "first" option and my data number decreased. When i used the right number of locations shifted by 0.1 m the krige. bayes did work this time. Now i have to figure out how much memory i do need to run the same function on a grid with about 15000 grid cells. If you have any info about that i will be really very grateful. Also i was searching for the "Ribeiro, P.J. Jr. and Diggle, P.J. (1999) _Bayesian inference in Gaussian model-based geostatistics_. Tech. Report ST-99-08, Dept Maths and Stats, Lancaster University.Available at: <URL: http://www.maths.lancs.ac.uk/~ribeiro/publications.html>" The link is invalidated now. Thank you so much for all your help and time, Monica