In the factored ZOH path introduced in PR #47, the flow is still: poles -> polynomial -> CCF A matrix. The polynomial step is redundant since the CCF A matrix could be constructed directly from the poles. Both the polynomial TF and the factored TF are currently passed in because the polynomial feeds tf_to_ss to get A for the B_d solve, while the factored path feeds the Vandermonde eigenvector construction. It may be possible to eliminate the polynomial entirely and build the CCF A matrix directly from the poles.
In the factored ZOH path introduced in PR #47, the flow is still: poles -> polynomial -> CCF A matrix. The polynomial step is redundant since the CCF A matrix could be constructed directly from the poles. Both the polynomial TF and the factored TF are currently passed in because the polynomial feeds tf_to_ss to get A for the B_d solve, while the factored path feeds the Vandermonde eigenvector construction. It may be possible to eliminate the polynomial entirely and build the CCF A matrix directly from the poles.