import numpy as np
import matplotlib.pyplot as plt
from matplotlib import cm
from matplotlib.ticker import LinearLocator, FormatStrFormatter
x=np.arange(-10,10,0.5)
y=x
X,Y=np.meshgrid(x,y)
def norm_d(x1,x2,mu1,mu2,s1,s2,rho):
num=((1)/(2*np.pi*s1*s2*np.sqrt(1-rho**2)))
A=((x1-mu1)**2)/(s1**2)
B=2*rho*(((x1-mu1)*(x2-mu2))/(s1*s2))
C=((x2-mu2)**2)/(s2**2)
D=-1/(2*(1-rho**2))*(A-B+C)
pdf=num*np.exp(D)
return 2dnm
R=norm_d(X,Y,0,0,1,3,0.75)
fig = plt.figure()
ax = fig.gca(projection=\'3d\')
surf = ax.plot_surface(X, Y, R, cmap=cm.coolwarm,linewidth=0, antialiased=False)
plt.show()
\\(\\sigma_1^2=1,\\sigma_2^2=3,\\rho=0.75\\)
\\(\\sigma_1^2=1,\\sigma_2^2=1,\\rho=0\\)
