Use set of values to calculate symbol size.

    values is a list of floats for candidate significance.
    inds is an optional list of indexes to use to calculate symbol size.
    Scaling of symbol size min max set by sizerange tuple (min, max).
    plaw is powerlaw scaling of symbol size from values

def calcsize(values, sizerange=(2,70), inds=None, plaw=3):
    """ Use set of values to calculate symbol size.

    values is a list of floats for candidate significance.
    inds is an optional list of indexes to use to calculate symbol size.
    Scaling of symbol size min max set by sizerange tuple (min, max).
    plaw is powerlaw scaling of symbol size from values
    """

    if inds:
        smax = max([abs(values[i]) for i in inds])
        smin = min([abs(values[i]) for i in inds])
    else:
        smax = max([abs(val) for val in values])
        smin = min([abs(val) for val in values])
    return [sizerange[0] + sizerange[1] * ((abs(val) - smin)/(smax - smin))**plaw for val in values]