本文介绍了如何在Python中使用其参数构造和绘制单变量高斯混合的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我想用Python中的三个组件构建和一维绘制一元高斯混合图,其中我已经有其参数,包括mu,sigma,mix factor.

I want to construct and 1D plot a uni-variate Gaussian Mixture with say three components in Python where I already have its parameters including mu,sigma,mix coefficients.

我追求的是在MATLAB中具有等效功能,即gmdistribution(mu,sigma,p)

What I am after has an equivalent in MATLAB i.e. gmdistribution(mu,sigma,p)

我认为代码应如下所示:

I think the code should look sth like this:

from numpy import *
from matplotlib.pylab import *
from sklearn import mixture

gmm = mixture.GMM(n_components=3)
gmm.means_ = np.array([[-1], [0], [3]])
gmm.covars_ = np.array([[1.5], [1], [0.5]]) ** 2
gmm.weights_ = np.array([0.3, 0.5, 0.2])
fig = plt.figure(figsize=(5, 1.7))

ax = fig.add_subplot(131)
#ax.plot(gmm, '-k') 

想知道如何做...

欢呼

推荐答案

假设高斯函数是独立的,并且要绘制pdf,则可以只组合按概率加权的基础高斯pdf:

Assuming the Gaussian's are independent, and you want to plot the pdf, you can just combine the underlying Gaussian pdfs weighted by the probabilities:

import numpy as np
import scipy.stats as ss
import matplotlib.pyplot as plt

means = -1., 0., 3.
stdevs = 1.5, 1., 0.5
weights = 0.3, 0.5, 0.2

x = np.arange(-5., 5., 0.01)

pdfs = [p * ss.norm.pdf(x, mu, sd) for mu, sd, p in zip(means, stdevs, weights)]

density = np.sum(np.array(pdfs), axis=0)
plt.plot(x, density)

这是正确的,需要一点基本概率论.

That this is correct requires a little elementary probability theory.

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09-18 04:17