I have an issue with my Phoenix Winnonlin ASCII model. Here's my differential equations:
DZ(2)=KA*Z(2) - KEL*Z(2)
DZ(3)=Constant *( 1 - ( 0.954 * IC50**Hill / ( (Z(2)/V*fu)**Hill + IC50**Hill ) ) ) - Constant*Z(3)
I get error message "Processing halted due to floating point error: INVALID NUMBER" when I use this hill parameter (temporary variable) and rational numbers such as 0.7 , 2.3 etc. There's also same error message when using simulation mode. Already I have resolved that simulation and parameter estimating work if I use whole number 0,1,2,3,4....
I have also other differential equations with exponent (used decimal numbers) but these work properly.