Structural model: one-compartment, oral absorption, multiple bolus dose, parameterized using KE.

This is a structural model function that encodes a model that is one-compartment, oral absorption, multiple bolus dose, parameterized using KE. The function is suitable for input to the create.poped.database function using the ff_fun or ff_file argument.

Usage

ff.PK.1.comp.oral.md.KE(model_switch, xt, parameters, poped.db)

Arguments

model_switch: a vector of values, the same size as xt, identifying which model response should be computed for the corresponding xt value. Used for multiple response models.
xt: a vector of independent variable values (often time).
parameters: A named list of parameter values.
poped.db: a poped database. This can be used to extract information that may be needed in the model file.

Value

A list consisting of:

y the values of the model at the specified points.
poped.db A (potentially modified) poped database.

Examples

library(PopED)

## find the parameters that are needed to define in the structural model
ff.PK.1.comp.oral.md.KE
#> function (model_switch, xt, parameters, poped.db) 
#> {
#>     with(as.list(parameters), {
#>         y = xt
#>         N = floor(xt/TAU) + 1
#>         y = (DOSE * Favail/V) * (KA/(KA - KE)) * (exp(-KE * (xt - 
#>             (N - 1) * TAU)) * (1 - exp(-N * KE * TAU))/(1 - exp(-KE * 
#>             TAU)) - exp(-KA * (xt - (N - 1) * TAU)) * (1 - exp(-N * 
#>             KA * TAU))/(1 - exp(-KA * TAU)))
#>         return(list(y = y, poped.db = poped.db))
#>     })
#> }
#> <bytecode: 0x564e4bca7138>
#> <environment: namespace:PopED>

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  ## -- parameter definition function 
  parameters=c( V=bpop[1]*exp(b[1]),
                KA=bpop[2]*exp(b[2]), 
                KE=bpop[3]*exp(b[3]),
                Favail=bpop[4],
                DOSE=a[1],
                TAU=a[2])
  return( parameters ) 
}

## -- Define design and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.md.KE,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  groupsize=20,
                                  m=2,
                                  sigma=c(0.04,5e-6),
                                  bpop=c(V=72.8,KA=0.25,KE=3.75/72.8,Favail=0.9), 
                                  d=c(V=0.09,KA=0.09,KE=0.25^2), 
                                  notfixed_bpop=c(1,1,1,0),
                                  notfixed_sigma=c(0,0),
                                  xt=c( 1,2,8,240,245),
                                  minxt=c(0,0,0,240,240),
                                  maxxt=c(10,10,10,248,248),
                                  a=cbind(c(20,40),c(24,24)),
                                  bUseGrouped_xt=1,
                                  maxa=c(200,40),
                                  mina=c(0,2))

##  create plot of model without variability 
plot_model_prediction(poped.db)


## evaluate initial design
FIM <- evaluate.fim(poped.db) 
FIM
#>             [,1]        [,2]         [,3]      [,4]     [,5]      [,6]
#> [1,]  0.06138421   -6.369454     34.30738    0.0000   0.0000    0.0000
#> [2,] -6.36945403 3667.860710   9887.52379    0.0000   0.0000    0.0000
#> [3,] 34.30737724 9887.523789 145132.13111    0.0000   0.0000    0.0000
#> [4,]  0.00000000    0.000000      0.00000 1322.9667 167.9800  206.8939
#> [5,]  0.00000000    0.000000      0.00000  167.9800 656.8986  202.6588
#> [6,]  0.00000000    0.000000      0.00000  206.8939 202.6588 1853.6889
det(FIM)
#> [1] 1.810534e+16
get_rse(FIM,poped.db)
#>         V        KA        KE       d_V      d_KA      d_KE 
#>  8.215338 10.090955  7.566975 31.220520 44.677836 38.005067

Structural model: one-compartment, oral absorption, multiple bolus dose, parameterized using KE.

Usage

Arguments

Value

See also

Examples