Hello, I want to use optim with simulated data. My program generates a sample and then calls optim to optimise a function that depends on the generated sample. I want to do this with 100 samples. But optim does not 'work' for the 100 samples, sometimes I get a message saying that sigma matrix was not invertible and therefore the optimisation was not carried out, and then my program breaks. Is there any way to implement a condition to avoid this? I mean, how can I specify that if this is the case, ignore such sample and try with the next one. Many thanks for your help Raquel
probably you want to look at ?try; I hope it helps. Best, Dimitris ---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/(0)16/336899 Fax: +32/(0)16/337015 Web: med.kuleuven.be/biostat student.kuleuven.be/~m0390867/dimitris.htm ----- Original Message ----- From: "R Granell, Medicine" <Raquel.Granell at bristol.ac.uk> To: <r-help at stat.math.ethz.ch> Sent: Thursday, May 11, 2006 12:18 PM Subject: [R] optim function> Hello, > > I want to use optim with simulated data. > My program generates a sample and then calls optim to optimise a > function > that depends on the generated sample. > > I want to do this with 100 samples. But optim does not 'work' for > the 100 > samples, sometimes I get a message saying that sigma matrix was not > invertible and therefore the optimisation was not carried out, and > then my > program breaks. > > Is there any way to implement a condition to avoid this? I mean, how > can I > specify that if this is the case, ignore such sample and try with > the next > one. > > Many thanks for your help > > Raquel > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > R-project.org/posting-guide.html >Disclaimer: kuleuven.be/cwis/email_disclaimer.htm