Hi - I am getting different results when I run the numerical integrator function lsoda (odesolve package) on a Mac and a PC. I am trying to simulating a system of 10 ODE's with two exogenous pulsed inputs to the system, and have had reasonably good success with many model parameter sets. Under some parameter sets, however, the simulations fail on the Mac (see error message below). The same parameter sets, however, appear to run fine for our computational technician on his PC, generating apparently very reasonable data.
Our tech is successfully running Dell Latitude D810, Windows XP Pro (Service Pack 2), 1Gb RAM. RGUI 2.1.1 I am running: R Version 2.1.1 (2005-06-20) on a Mac OS 10.3.9 Machine Model: Power Mac G5 CPU Type: PowerPC 970 (2.2) Number Of CPUs: 2 CPU Speed: 2 GHz L2 Cache (per CPU): 512 KB Memory: 1.5 GB Bus Speed: 1 GHz Boot ROM Version: 5.0.7f0 Serial Number: XB3472Q1NVS My Error Message > system.time( + outAc2 <- as.data.frame(lsoda(xstart,times, pondamph, parms, tcrit=170*730, hmin=.1)) + ) [1] 0.02 0.01 0.04 0.00 0.00 Warning messages: 1: lsoda-- at t (=r1) and step size h (=r2), the 2: corrector convergence failed repeatedly 3: or with abs(h) = hmin 4: Returning early from lsoda. Results are accurate, as far as they go Thanks for any input. Hank Stevens Dr. Martin Henry H. Stevens, Assistant Professor 338 Pearson Hall Botany Department Miami University Oxford, OH 45056 Office: (513) 529-4206 Lab: (513) 529-4262 FAX: (513) 529-4243 http://www.cas.muohio.edu/botany/bot/henry.html http://www.muohio.edu/ecology/ http://www.muohio.edu/botany/ "E Pluribus Unum" ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
