听起来您正在寻找的是多元正态分布。这在scipy中实现为scipy.stats.multivariate_normal。重要的是要记住,您正在将协方差矩阵传递给函数。因此,为了简单起见,请将对角线元素设为零:
[X variance , 0 ][ 0 ,Y Variance]
这是使用此功能并生成结果分布的3D图的示例。我添加了颜色图,使查看曲线更容易,但可以随时将其删除。
import numpy as npimport matplotlib.pyplot as pltfrom scipy.stats import multivariate_normalfrom mpl_toolkits.mplot3d import Axes3D#Parameters to setmu_x = 0variance_x = 3mu_y = 0variance_y = 15#Create grid and multivariate normalx = np.linspace(-10,10,500)y = np.linspace(-10,10,500)X, Y = np.meshgrid(x,y)pos = np.empty(X.shape + (2,))pos[:, :, 0] = X; pos[:, :, 1] = Yrv = multivariate_normal([mu_x, mu_y], [[variance_x, 0], [0, variance_y]])#Make a 3D plotfig = plt.figure()ax = fig.gca(projection='3d')ax.plot_surface(X, Y, rv.pdf(pos),cmap='viridis',linewidth=0)ax.set_xlabel('X axis')ax.set_ylabel('Y axis')ax.set_zlabel('Z axis')plt.show()给你这个情节:
编辑下面使用的方法在Matplotlib v2.2中已弃用,在v3.1中已删除
可通过
matplotlib.mlab.bivariate_normal获得一个更简单的版本。
它采用以下参数,因此您不必担心矩阵。 matplotlib.mlab.bivariate_normal(X, Y, sigmax=1.0,sigmay=1.0, mux=0.0, muy=0.0, sigmaxy=0.0)
这里X和Y再次是Meshgrid的结果,因此可以使用它来重新创建上述图:
import numpy as npimport matplotlib.pyplot as pltfrom matplotlib.mlab import bivariate_normalfrom mpl_toolkits.mplot3d import Axes3D#Parameters to setmu_x = 0sigma_x = np.sqrt(3)mu_y = 0sigma_y = np.sqrt(15)#Create grid and multivariate normalx = np.linspace(-10,10,500)y = np.linspace(-10,10,500)X, Y = np.meshgrid(x,y)Z = bivariate_normal(X,Y,sigma_x,sigma_y,mu_x,mu_y)#Make a 3D plotfig = plt.figure()ax = fig.gca(projection='3d')ax.plot_surface(X, Y, Z,cmap='viridis',linewidth=0)ax.set_xlabel('X axis')ax.set_ylabel('Y axis')ax.set_zlabel('Z axis')plt.show()给予:



