[R-sig-dyn-mod] how to pulse input

[Jinsong Zhao]

Hi there,

I want to affect a model with pulse input. Now I do this something like 
this:

C_Only <- function(time, state, parameters) {
     with(as.list(c(state,parameters)), {
          # rate of change
          Dc <- Kd * Enzc
### pulse input at time = 25 ###
          if (time >= 25 & time < 26) Uc <- 10 + Dc else Uc <- DOC + Dc
###
          print(c(time, Uc))
          EPc <- Ke * Uc
          ELc <- Kl * Enzc
          Re <- EPc * (1 - SUE) / SUE
          Rm <- Km * Biomc
          Rg <- (Uc - EPc - Re - Rm) * (1 - SUE)
          dEnzc <- EPc - ELc
          dBiomc <- Uc - EPc - Re - Rm - Rg
          # return the rate of change
          list(c(dEnzc, dBiomc))
     })
}

Is it the correct way to set pulse input? How I can set the pulse input 
time within function argument?

Any help will be really appreciated.

Best wishes,
Jinsong