def radius_calculator(centers):
    """Given a list of centers, makes a list of the distances between the
       centers."""
    distances = []

    # Iterates through each center in comparison to all other centers
    for a in centers:
        for b in centers:
            # Ensures each radius is only counted once
            if centers.index(a) < centers.index(b):
                radius = ((a[0] - b[0]) ** 2 + (a[1] - b[1]) ** 2) ** .5
                distances.append(radius)

    return distances