def cliped_rand_norm(mu=0, sigma3=1): """ :param mu: 均值 :param sigma3: 3 倍标准差, 99% 的数据落在 (mu
只不过 $\ln(x)$ 服从正态分布,取 $\mu - 3\sigma, \mu + 3\sigma$ ;那么 $x$ 就应该取 $e^{\mu-3\sigma}, e^{\mu+3\sigma}$,
数据的数值分布几乎全部集中在区间 (\mu-3,\mu+3) 内,超出这个范围的数据仅占不到 0.3\% 。故根据小概率原理,可以认为超出 3\sigma 的部分数据为异常数据。
图1: 3sigma def three_sigma(s): mu, std = np.mean(s), np.std(s) lower, upper = mu-3*std, mu+
图1: 3sigma def three_sigma(s): mu, std = np.mean(s), np.std(s) lower, upper = mu-3*std, mu+
图1: 3sigma def three_sigma(s): mu, std = np.mean(s), np.std(s) lower, upper = mu-3*std, mu+3*
图1: 3sigma def three_sigma(s): mu, std = np.mean(s), np.std(s) lower, upper = mu-3*std, mu+3*
图1: 3sigma def three_sigma(s): mu, std = np.mean(s), np.std(s) lower, upper = mu-3*std, mu+3*
若已知某零件的正常尺寸均值为μ\muμ,标准差为σ\sigmaσ,根据3σ3\sigma3σ原则,当零件尺寸超出(μ−3σ,μ+3σ)(\mu-3\sigma,\mu+3\sigma)(μ−3σ,μ+3σ