def logLogisticCDF(x, alpha, beta, omga):
    """ x : non-negative  data series
      Cumulative distribution function of a three parameter Log-logistic distributin  (Fisk distribution)
        scale=.1
        shape=3
        loc=5
        x=7
        logLogisticCDF(x,scale, shape,loc)
        0.9998750156230471"""
    return 1 / (1 + pow(alpha / (x - omga), beta))
