def alpha_(self,x):
        """ Create a mappable function alpha to apply to each xmin in a list of xmins.
        This is essentially the slow version of fplfit/cplfit, though I bet it could
        be speeded up with a clever use of parellel_map.  Not intended to be used by users."""
        def alpha(xmin,x=x):
            """
            given a sorted data set and a minimum, returns power law MLE fit
            data is passed as a keyword parameter so that it can be vectorized
            """
            x = [i for i in x if i>=xmin]
            n = sum(x)
            divsum = sum([math.log(i/xmin) for i in x])
            if divsum == 0:
                return float('inf')
            # the "1+" here is unimportant because alpha_ is only used for minimization
            a = 1 + float(n) / divsum
            return a
        return alpha
Create a mappable function alpha to apply to each xmin in a list of xmins.
        This is essentially the slow version of fplfit/cplfit, though I bet it could
        be speeded up with a clever use of parellel_map.  Not intended to be used by users.