def arelfreq(a,numbins=10,defaultreallimits=None):
    h,l,b,e = histogram(a,numbins,defaultreallimits)
    h = N.array(h/float(a.shape[0]))
    return h,l,b,e


#####################################
######  AVARIABILITY FUNCTIONS  #####
#####################################
Returns a relative frequency histogram, using the histogram function.
dataset/ETHPy150Open radlab/sparrow/src/main/python/third_party/stats.py/arelfreq