rxFixPop function

Apply the fixed population estimated parameters

rxFixPop(ui, returnNull = FALSE)

Arguments

• ui: rxode2 ui function
• returnNull: boolean for if unchanged values should return the original ui (FALSE) or null (TRUE)

Returns

when returnNull is TRUE, NULL if nothing was changed, or the changed model ui. When returnNull is FALSE, return a ui no matter if it is changed or not.

Examples

One.comp.transit.allo <- function() {
 ini({
   # Where initial conditions/variables are specified
   lktr <- log(1.15)  #log k transit (/h)
   lcl  <- log(0.15)  #log Cl (L/hr)
   lv   <- log(7)     #log V (L)
   ALLC <- fix(0.75)  #allometric exponent cl
   ALLV <- fix(1.00)  #allometric exponent v
   prop.err <- 0.15   #proportional error (SD/mean)
   add.err <- 0.6     #additive error (mg/L)
   eta.ktr ~ 0.5
   eta.cl ~ 0.1
   eta.v ~ 0.1
 })
 model({
   #Allometric scaling on weight
   cl <- exp(lcl + eta.cl + ALLC * logWT70)
   v  <- exp(lv + eta.v + ALLV * logWT70)
   ktr <- exp(lktr + eta.ktr)
   # RxODE-style differential equations are supported
   d/dt(depot)   = -ktr * depot
   d/dt(central) =  ktr * trans - (cl/v) * central
   d/dt(trans)   =  ktr * depot - ktr * trans
   ## Concentration is calculated
   cp = central/v
   # And is assumed to follow proportional and additive error
   cp ~ prop(prop.err) + add(add.err)
 })
}

m <- rxFixPop(One.comp.transit.allo)
m

# now everything is already fixed, so calling again will do nothing

rxFixPop(m)

# if you call it with returnNull=TRUE when no changes have been
# performed, the function will return NULL

rxFixPop(m, returnNull=TRUE)

Author(s)

Matthew L. Fidler