import numpy as np
import matplotlib.pyplot as plt

gaus = lambda x,mu,sigma: np.exp(-0.5*(x-mu)**2/sigma**2)/sigma/2**0.5

fig = plt.figure(figsize=(6,4), dpi=80)
x = np.linspace(-10.,10.,1000)
for w in [0.5,1.,2.,3.,4.]:
    y = gaus(x, 0., w)
    plt.plot(x,y)
plt.show()