A time-dependent minimization problem for the computation of a mixed L-2-Wa
sserstein distance between two prescribed density functions is introduced i
n the spirit of Ref. 1 for the classical Wasserstein distance. The optimum
of the cost function corresponds to an optimal mapping between prescribed i
nitial and final densities. We enforce the final density conditions through
a penalization term added to our cost function. A conjugate gradient metho
d is used to solve this relaxed problem. We obtain an algorithm which compu
tes an interpolated L-2-Wasserstein distance between two densities and the
corresponding optimal mapping.