Hello, I am new to R and I am having problems trying to model logistic population growth with the deSolve package. I would like to run the model for four populations with the same initial population and carrying capacity but with different growth rates and put the results into a data frame. When I run the following lines of code I get unexpected results from "output" but the format is more or less what I am looking for. When I run the function, I get the results I expected but for only one time step. I haven't been able to discern what the problem is and haven't gotten any error messages to clue me in on where I am making a mistake. Advice would be grealty appreciated. Thanks.
library(deSolve) parameters = c(K=305, ra=0.8, rb=1.5, rc=2.1, rd=2.6) state = c(Na=5, Nb=5, Nc=5, Nd=5) logGrowth = function(time, state, parameters) { with(as.list(c(state,parameters)), { dNa.dt = ra * Na * (1-(Na/K)) dNb.dt = rb * Nb * (1-(Nb/K)) dNc.dt = rc * Nc * (1-(Nc/K)) dNd.dt = rd * Nd * (1-(Nd/K)) return(list(c(dNa.dt, dNb.dt, dNc.dt, dNd.dt))) }) } times = 1:20 output = ode(y = state, times = times, func = logGrowth, parms = parameters) print(output) logGrowth(times,state,parameters) -- View this message in context: http://r.789695.n4.nabble.com/Logistic-population-growth-and-deSolve-tp4353655p4353655.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org 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.