********** MODEL NAME
complex covariate model

********** MODEL NOTES

Example for a more complex covariate model, requiring regression parameters

********** MODEL STATES

d/dt(Ad) 	= -ka*Ad + INPUT1
d/dt(Ac) 	=  ka*Ad - CLx/Vc*Ac - Q1/Vc*Ac + Q1/Vp1*Ap1 
d/dt(Ap1)   =                      Q1/Vc*Ac - Q1/Vp1*Ap1

Ad(0) 	 	= 0
Ac(0)    	= 0
Ap1(0)    	= 0

********** MODEL PARAMETERS

ka 			  = 2   # Absorption rate parameter (1/hour)
CL 			  = 3 	# Apparent clearance (L/hour)
Vc 			  = 32 	# Apparent central volume (L)
Q1			  = 1 	# Apparent intercompartmental clearance (L/hour)
Vp1			  = 10 	# Apparent peripheral volume (L)
Tlag1         = 0   # Absorption lag time (hours)

WT0           = 70  # Regression parameter (kg)
AGE0          = 35  # Regression parameter (years)
beta1         = 0   # First covariate model parameter
beta2         = 0   # Second covariate model parameter

********** MODEL VARIABLES

% Implementation of more complex covariate model on CL
CLx           = CL*(AGE0-40)^beta1/WT0^beta2

% Calculation of concentration in central compartment
Cc 			  = Ac/Vc

% Defining an output (only needed when interfacing with NLME
% parameter estimation tools such as NONMEM and MONOLIX)
OUTPUT1  	  = Cc  # Compound concentration 


********** MODEL REACTIONS


********** MODEL FUNCTIONS


********** MODEL EVENTS