Computation of Principal A-determinants through Dimer Dynamics

In this note we translate the pictorial description of Gulotta’s efficient inverse algorithm (arXiv:0807.3012) into matrix operations, so that it can be implemented on a computer. As an application we point out that this in combination with results from our paper arXiv:0803.3908 provides a fast algorithm for computing the principal A-determinant of Gelfand, Kapranov and Zelevinsky for hypergeometric systems in two variables.