def get_intersections(self,istart,iend):
        indices = []
        self.intervals.sort(lambda x,y:cmp(x[0],y[0]))
        current_point = istart
        while (True):
            actives = filter(lambda x:x[0] <= current_point and
                              x[1] >= current_point,self.intervals)
            if len(actives) == 0:
                break
            indices.append(map(lambda x: x[2],actives))
            if (current_point >= iend): break
            current_point = min(
                    filter(lambda x: x>current_point,self.points),
                                )   
            if (current_point >= iend): break
        return indices
return the id of intervals intersecting with [istar,iend] at each of the discontinuity points
dataset/ETHPy150Open fp7-ofelia/ocf/optin_manager/src/python/openflow/optin_manager/flowspace/helper.py/Intervals.get_intersections