I am trying to run a PK-Imax model, which runs very well (apparently) until attempting to estimate the the fisher information matrix.
An error message appears ‘execution error, matrix dimensions must agree’. I can’t understand why this is appearing, as population parameters are produced by the model and IIV is estimated well ..
Has anyone seen this before?
Here is the structural model, if that is any help?..The PK model has 2 residual errors (one for each dataset used – CSan (single dose study) and Cad (steady state study on the same drug))
The PD model estimated D2 receptor occupancy, quantified by imaging, where Cau0 = binding of the tracer at baseline and Cau Occ = proportion of receptors occupied post- treatment