def METHOD_NAME(ps, bgvals):
    crb3d = []
    vol = []
    #I = ps[:,:,ps.shape[2]/2].sum()
    for bg in bgvals:
        #print bg
        crb = genCRB(ps + I*bg/2000.)
        crb3d.append(np.sqrt(crb.sum(1))[20:-20].mean())
        vol.append(np.sqrt(crb).prod(1)[20:-20].mean())
    return np.array(crb3d), np.array(vol)