George Perendia george@perendia.orangehome.co.uk writes:
Can we then please include C Sims' qzcomplex.oct package and build it into our releases for Octave PI users because it saves us from changing our code further?
I am going to take care of that.
Note: I.e. whilst sparse "a" matrices seem fully identical and all other matrices from qzcomplex and qz Matlab have identical numbers in the same place (except for q from qzcomplex having form of transposed q from Matlab qz()), the most of matrices from qzcomplex (i.e. b, q and z, except for a?) have the most of their numbers with opposite signs, both their real and their imaginary parts being affected and, as well the real-only numbers too (except where the number is 1). However, the final results of the saddlepath condition Nmat are nevertheless the same.
It is normal to get differences in the matrices Q and Z, because the QZ decomposition is not unique with respect to these matrices. For A and B you should get at least the same diagonals (up to reordering), because the generalized eigenvalues are uniquely defined.