  We present finite-element numerical algorithms for the identification of
vortices in quantum fluids described by a macroscopic complex wave function.
Their implementation using the free software FreeFem++ is distributed with this
paper as a post-processing toolbox that can be used to analyse numerical or
experimental data. Applications for Bose-Einstein condensates (BEC) and
superfluid helium flows are presented. Programs are tested and validated using
either numerical data obtained by solving the Gross-Pitaevskii equation or
experimental images of rotating BEC. Vortex positions are computed as
topological defects (zeros) of the wave function when numerical data are used.
For experimental images, we compute vortex positions as local minima of the
atomic density, extracted after a simple image processing. Once vortex centers
are identified, we use a fit with a Gaussian to precisely estimate vortex
radius. For vortex lattices, the lattice parameter (inter-vortex distance) is
also computed. The post-processing toolbox offers a complete description of
vortex configurations in superfluids. Tests for two-dimensional (giant vortex
in rotating BEC, Abrikosov vortex lattice in experimental BEC) and
three-dimensional (vortex rings, Kelvin waves and quantum turbulence fields in
superfluid helium) configurations show the robustness of the software. The
communication with programs providing the numerical or experimental wave
function field is simple and intuitive. The post-processing toolbox can be also
applied for the identification of vortices in superconductors.
