code (sage)
Here you can find Sage worksheets with code to define a class of flow polytopes of type A, B, C, D.
Requirements:
Sage 5.9 or higher
installing lrs optional package using sage -i lrs (or see post)
Setup:
download flowpolytopeA.sws and open the worksheet using the Sage notebook (for type A flow polytopes)
download flowpolytopeCBD.sws and open the worksheet using the Sage notebook (for type B, C, D flow polytopes)
Alternatively, worksheets available in SageMathCloud: