I am a new user for Pheonix. It is a very nice software that allows you to catch up very quickly. I enjoy using it very much. However, I have come across a question and would appreciate any inputs. So I am modeling a two compartment plasma and urinary data simultaneously using the following codes in phoenix. I was able to get good estimates on my parameters. However, I also specified a secondary parameter Fe (fraction of renal elimination). After finishing estimation, I go into “secondary” in the Results → Output Data tab. I notice that for the secondary parameter Fe, no standard error, CV%, or confidence interval was given. Only a point estimate for Fe was given, supposedly calculated using the typical value of the primary parameters estimated. It would be nice to also be able to report the dispersion on secondary parameters. Is there a way to do this in pheonix? Thank you so much. — Jason test(){ Cp = Aexp(-alphat)+Bexp(-betat) deriv(A2 = ClrCp) error(CEps = 1) observe(CObs = Cp(1+CEps)) observe(AObs = A2*(1+CEps)) stparm(A = tvA) stparm(B = tvB) stparm(alpha = tvalpha) stparm(beta = tvbeta) stparm(Clr = tvClr) fixef(tvA = c(, 450, )) fixef(tvB = c(, 20, )) fixef(tvalpha = c(, 0.9, )) fixef(tvbeta = c(, 0.1, )) fixef(tvClr = c(, 8, )) secondary(Fe=Clr/(Dose/(A/alpha+B/beta))) Dose = 10000 }
Dear Jason Can you try that code instead. I used only the tv parameters rather than the parameters.I think the program expects you to use the secondary parameters a s afunciton of the typical values defined on the right sde of the stparm statement.It should work that way. Let me know if it helps. best Serge test(){ Cp = Aexp(-alphat)+Bexp(-betat) deriv(A2 = ClrCp) error(CEps = 0.1) observe(CObs = Cp(1+CEps)) observe(AObs = A2*(1+CEps)) stparm(A = tvA) stparm(B = tvB) stparm(alpha = tvalpha) stparm(beta = tvbeta) stparm(Clr = tvClr) fixef(tvA = c(, 450, )) fixef(tvB = c(, 20, )) fixef(tvalpha = c(, 0.9, )) fixef(tvbeta = c(, 0.1, )) fixef(tvClr = c(, 8, )) Dose = 10000 secondary(Fe=tvClr/(Dose/(tvA/tvalpha+tvB/tvbeta))) }
It works great by adding “tv” to all parameters in the “secondary” statement. Thank you so much!
Any time Bst Serge