def acumfreq(a,numbins=10,defaultreallimits=None):
    h,l,b,e = histogram(a,numbins,defaultreallimits)
    cumhist = cumsum(h*1)
    return cumhist,l,b,e
Returns a cumulative frequency histogram, using the histogram function.
dataset/ETHPy150Open radlab/sparrow/src/main/python/third_party/stats.py/acumfreq