3 replies to this topic

[Cornelia Preusse]

Hello,
I just tried to implement a literature model to test additivity of co-administrated anticancer drugs into Phoenix 6.2. (Rocchetti et al. 2009). This model consists of 7 parameters and 17 differential equations.
I’m getting the error message:
Error in Population:
Error: Number of differential equations (17) times number of random effects (6 + 1) exceeds limit of approx. 100. Der Befehl "".\NLME7.exe"" ist entweder falsch geschrieben oder konnte nicht gefunden werden.
Model execution failed or cancelled
If I reduce the number of parameters and replace them by fixed statements, the model runs, but that’s obviously not what I would like to do.
Does anybody has any suggestions or workarounds ?

[Simon Davis]

Cornelia,

 Which version of Phoenix are you using? There were some restrictions previously but I thought most of those had been raised.

 

 Is it possible you can post the project (or email it to support@pharsight.com) so we can investigate further.

 

 Simon.

[Cornelia Preusse]

Hi Simon,

I'm running version 6.2. I attached the project below. Thanks for your help,

Conny [file name=Rocchetti_additive.phxproj size=665285]http://www.pharsight.com/extranet/media/kunena/attachments/legacy/files/Rocchetti_additive.phxproj[/file]

[Simon Davis]

Cornelia - this code executes in 6.3 without that error message.

Note that in you present code you have not set initial estimates, remember in textual mode they need to be transferred manually to this section.

fixef(tvk1a = c(, 1, ))
fixef(tvk1b = c(, 1, ))
fixef(tvk2a = c(, 1, ))
...

also I just wanted to check, this was a repeated dose study right? doses every 96 h or thereabouts? I suggest you get the 6.3 version (released in March) and work with that, page 18 of the release notes covers your limitation;

Error: Number of differential equations (5) times number of random effects (28 + 1)
exceeded limit of approximately 100 (QC 10923): The generation of sensitivity
equations is now done only when needed, in order to not balloon the number of ODEs.
This error message should only occur now when the limits are truly exceeded.

Simon.

For what it's worth here are the first few lines of the run with the default initial estimates.
# Population:
# NLME7 built Mar 19 2012, 11:59:42
# ODE level: requested, used = 6, 3
# ODE levels: 6=matexp, 5=LSODA(ana jac), 4=LSODA(num jac), 3=RK, 2=stiff(ana jac), 1=stiff(num jac), 0=none
ReturnCode = -1
LLLaplace = 72.88710
EpsShrinkage = -2.66014
NParm = 13
NObs = 40
NSub = 4

fixed effects
theta[0] = 0.00216687 # tvk1a
theta[1] = 2.66264 # tvk1b
theta[2] = -6.31396e-006 # tvk2a
theta[3] = 2.45986e-005 # tvk2b
theta[4] = -0.261383 # tvlamda0
theta[5] = -0.00164338 # tvlamda1
theta[6] = 0.0270697 # CEps