Hello, I would like to raise a question regarding the FastCC implementation of Cobrapy. After multiple runs, FastCC outputs a different number of blocked reactions using the Recon1 model. It might be reasonable because optimization never delivers unique solutions. But, the respective MATLAB function from the COBRAToolbox always returns the same results after several runs. Since both implementations are based on the same algorithm, I guess both should give the same results. So, I think this might be something worths checking.

I noticed that the number of irreversible reactions detected in the FastCC implementation deviates from the number of irreversible reactions computed by the MATLAB function. Reactions that are irreversible in the backward direction are not reported as irreversible in the MATLAB command window.

For Recon1:
MATLAB:

• 2186 irreversible reactions
• 1274 blocked reactions

Python:

• 2192 irreversible reactions
• blocked reactions differ after each run
  Used solver: glpk, python 3.8.5