Jump to content


Photo

TIP: How to add biovailability in my PML model


  • Please log in to reply
1 reply to this topic

#1 Ana Henry

Ana Henry

    Advanced Member

  • Members
  • PipPipPip
  • 227 posts

Posted 14 September 2011 - 02:57 PM

In order to estimate biovailabilty in a PML model you can add the following code to the dosepoint of the absorption compartment

 

dosepoint(Aa, bioavail = F)

 

and then deifne the parameter F and its initial values

 

stparm(F = ....)

fixef (F= c(0,0.5,1))



#2 Jason Chittenden

Jason Chittenden

    Member

  • Members
  • PipPip
  • 17 posts

Posted 14 September 2011 - 03:24 PM

I'll add to this topic. If you want to have a random effect on bioavailability, you'll want to limit the support of the structural parameter to values between (but not including) zero and one, like this:

 

stparm( F = ilogit( tvpF + npF) )

fixef( tvpF = 0) #some initial value

ranef(...,npF,...) = ...

 

ilogit is the inverse logit function, or logistic function. I use the "p" in my variables to remind myself that these values undergo a logistic transformation.






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users