search for: yini

...Thanks, Vince CODE: library(deSolve) Res_DAE=function(t, y, dy, pars) { with(as.list(c(y, dy, pars)), { res1 = -dS -dES-k2*ES res2 = -dP + k2*ES eq1 = Eo-E -ES eq2 = So-S -ES -P return(list(c(res1, res2, eq1, eq2))) }) } pars <- c(Eo=0.02, So=0.02, k2=250, E=0.01); pars yini <- c(S=0.01, ES = 0.01, P=0.0, E=0.01); yini times <- seq(0, 0.01, by = 0.0001); times dyini = c(dS=0.0, dES=0.0, dP=0.0) ## Tabular output check of matrix output DAE <- daspk(y = yini, dy = dyini, times = times, res = Res_DAE, parms = pars, atol = 1e-10, rtol = 1e-10) ERROR: daspk-- w...

...Thanks, Vince CODE: library(deSolve) Res_DAE=function(t, y, dy, pars) { with(as.list(c(y, dy, pars)), { res1 = -dS -dES-k2*ES res2 = -dP + k2*ES eq1 = Eo-E -ES eq2 = So-S -ES -P return(list(c(res1, res2, eq1, eq2))) }) } pars <- c(Eo=0.02, So=0.02, k2=250, E=0.01); pars yini <- c(S=0.01, ES = 0.01, P=0.0, E=0.01); yini times <- seq(0, 0.01, by = 0.0001); times dyini = c(dS=0.0, dES=0.0, dP=0.0) ## Tabular output check of matrix output DAE <- daspk(y = yini, dy = dyini, times = times, res = Res_DAE, parms = pars, atol = 1e-10, rtol = 1e-10) ERROR: daspk-- w...

Hello All, I'm struggling to solve this ODE using R, vdpol <- function (h, v, t) ( list(c ( -0.1*v/(pi*(2*10*h-h^2)), (v = (-0.1*v/(pi*(2*10*h-h^2))^2) + 2*9.81*h)) )) library(deSolve) yini <- (c(h = 20, v=0)) nonstiff <- ode(y = yini, func = vdpol, times= seq(0, 30, by = 0.01), parms = 1) It says that The number of derivatives returned by func() (4) must equal the length of the initial conditions vecto...

Dear List, Wonder if you have some thoughts on the following question using lsoda in desolve: I have the following data and function: require(deSolve) times <- c(0:24) tin  <- 0.5 D <- 400 V    <- 26.3 k <-0.056 k12  <- 0.197118 k21  <- 0.022665 yini <- c(dy1 = 0,dy2 = 0)  events <- data.frame(var = "dy1",time = c(10,15),value = c(200,100),method = "add") pkmod <- function(t, y, p) {   if (t < tin) R <- (D/tin) else R <- 0   dy1 <- R - (p["k12"]+p["k"])* y[1] + p["k21"]*y[2]...

...these parameters as a vector this productes and error rGrow = c(1.0, 1.3, 1.7) # /day, growth rate of prey rMort = 0.2 , # /day, mortality rate of predator assEff = 0.5, # -, assimilation efficiency K = 10) # mmol/m3, carrying capacity yini <- c(Prey = c(1, 2,3), Predator = 2) times <- seq(0, 200, by = 1) out <- ode(yini, times, LVmod, pars) summary(out) Thanks Frank

...with(as.list(c(State, Pars)), { IngestPred <- rI * N * Pred GrowthN <- rG * N * (1 - N/K) MortPred <- rM * Pred dN <- GrowthN - IngestPred dPred <- IngestPred * AE - MortPred return(list(c(dN, dPred))) }) } pars <- c(rI = 0.1, rG = 0.9, rM = 0.8, AE = 0.9, K = 20) yini <- c(N = 20, Pred = 20) times <- seq(0, 200, by = 1) y(time=100)<-c(N=10, Pred=5) print(system.time) zout <- as.data.frame(lsoda(yini, y(time=100), times, LVmod0D, pars)) plot(zout[,1],zout[,2], type="l",col="black", ylim=range(0,25), xlab="time",ylab=...