R Users, I have written a small simulation model in R which outputs a datafile consisting of ending population sizes for each simulation run (year). The data (see short data example below) is labeled by NUM (simulation run), sim (year) and N (yearly count). After searching the help files and coming up empty (probably because I used the wrong terms) I am appealing for some help for working with the output dataset.
What I want to do is for each of the i simulation runs (NUM) I want to 1) take N(t+1)/N(t)=lambda(t) for each year (where in the below example t=1,...,10--total years of the simulation) 2) Sum lambda(t) and divide by t (e.g., output both the mean/se of lambda for each simulation run) 3) Take the mean of the mean(lambda's) (and associated stddev, min, max) over all NUM I think I have to write a function for use within an apply statement, but I am not quite there yet on the learning curve so most of my recent attempts in R have been useful learning experiences of what not to do... Any suggestions/direction is greatly appreciated. Bret Collier TX A&M NUM sim N 1 1 466 1 2 450 1 3 473 1 4 531 1 5 515 1 6 502 1 7 471 1 8 460 1 9 458 1 10 434 2 1 289 2 2 356 2 3 387 2 4 440 2 5 457 2 6 466 2 7 467 2 8 449 2 9 387 2 10 394 3 1 367 3 2 400 3 3 476 3 4 508 3 5 478 3 6 501 3 7 513 3 8 505 3 9 492 3 10 465 platform i386-pc-mingw32 arch i386 os mingw32 system i386, mingw32 status major 2 minor 3.0 year 2006 month 04 day 24 svn rev 37909 language R version.string Version 2.3.0 (2006-04-24) (yeah, I need to update) ______________________________________________ [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 and provide commented, minimal, self-contained, reproducible code.
