[R-sig-dyn-mod] Help with function

[Austin Mullings]

Daniel,



On Tue, Feb 17, 2015 at 2:04 AM, Daniel Kaschek <
daniel.kaschek at physik.uni-freiburg.de> wrote:

> Hi Austin,
>
> one possibility to do this is the code below. In this example code, I
> randomly initialize your parameters and the initial state. Instead of
> using the indexes to access parameter values or states you can use the
> names as well (see ?ode, first example). However, in my experience, the
> function with() slows down your code considerably.
>
> Best wishes,
> Daniel
>
>
> library(deSolve)
>
> myfn <- function(t, y, p) {
>
>   dy <- numeric(6)
>   dy[1] <- p[1] - p[2]*y[4] - p[3]*y[1]
>   dy[2] <- y[5]*dy[1]*(1+y[6]) - p[5]*y[2] - (p[6]*y[3]*y[4]*y[1] - p[7])
>   dy[3] <- p[8] - p[9]*y[2]
>   dy[4] <- y[6]*dy[1] - p[10]*y[4] + p[11]*(p[6]*y[3]*y[4]*y[1] - p[7]) +
> p[4]
>   dy[5] <- 1.0 - y[5]*(y[1] + y[4] + 1)
>   dy[6] <- 1.0 - y[6]*(y[1] + 1)
>
>   return(list(dy))
>
> }
>
> pars <- runif(11)
> yini <- runif(6)
> times <- seq(0, 10, .01)
>
>
> out <- ode(yini, times, myfn, pars)
> plot(out)
>
>
> On Mo, 2015-02-16 at 13:15 -0700, Austin Mullings wrote:
> > I am trying to get this equation to work with deSolve, and can't seem to
> > get it to work. Does someone know how one would write the function for
> this?
> >
> > dY1(t)/dt = a - bY3(t) Y4(t) - cY1(t),
> > dY2(t)/dt = Y5(t) [dY1(t)/dt] [1 + Y6(t)] - eY2(t) - {f Y3(t) Y4(t)
> Y1(t) -
> > g},
> > dY3(t)/dt = h - iY2(t),
> > dY4(t)/dt = Y6(t) [dY1(t)/dt] - jY4(t) + k {f Y3(t) Y4(t) Y1(t) - g} + d,
> > dY5(t)/dt = 1.0 - Y5(t) [Y1(t) + Y4(t) + 1],
> > dY6(t)/dt = 1.0 - Y6(t) [Y1(t) + 1].
> >
> >       [[alternative HTML version deleted]]
> >
> > _______________________________________________
> > R-sig-dynamic-models mailing list
> > R-sig-dynamic-models at r-project.org
> > https://stat.ethz.ch/mailman/listinfo/r-sig-dynamic-models
>
> --
> Daniel Kaschek
> Institute of Physics
> Freiburg University
>
> Room 210
> Phone: +49 761 2038531
>
> _______________________________________________
> R-sig-dynamic-models mailing list
> R-sig-dynamic-models at r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-dynamic-models
>



-- 
Austin F. Mullings
Graduate Student, Research Assistant
Department of Psychology, Clinical Psychology
University of Colorado at Colorado Springs

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