def _min_distance(x, y, z):
    distances = numpy.sqrt((x.reshape((-1,)) - x.reshape((1, -1))) ** 2
                           + (y.reshape((-1,)) - y.reshape((1, -1))) ** 2
                           + (z.reshape((-1,)) - z.reshape((1, -1))) ** 2
                          )
    return distances[distances != 0].min()
return list of reachable head sha ids or (names, sha) pairs if resolve is true
dataset/ETHPy150Open enthought/mayavi/mayavi/tools/tools.py/_min_distance--crossover with--dataset/ETHPy150Open hvr/trac-git-plugin/tracext/git/PyGIT.py/Storage.get_branch_contains