先看实现的效果，有一个形象的认识。

这样一副图怎么画出来呢？

用python将变得很简单，看代码吧！

import mathimport pylab as plimport numpy as npdef gd(x,m,s):    left=1/(math.sqrt(2*math.pi)*s)    right=math.exp(-math.pow(x-m,2)/(2*math.pow(s,2)))    return left*rightdef showfigure():    x=np.arange(-4,5,0.1)    y=[]    for i in x:        y.append(gd(i,0,1))    pl.plot(x,y)      pl.xlim(-4.0,5.0)    pl.ylim(-0.2,0.5)#    ax = pl.gca()    ax.spines['right'].set_color('none')    ax.spines['top'].set_color('none')    ax.xaxis.set_ticks_position('bottom')    ax.spines['bottom'].set_position(('data',0))    ax.yaxis.set_ticks_position('left')    ax.spines['left'].set_position(('data',0))    #add param    label_f1 = "$\mu=0,\ \sigma=1$"    pl.text(2.5,0.3,label_f1,fontsize=15,verticalalignment="top",            horizontalalignment="left")    label_f2 = r"$f(x)=\frac{1}{\sqrt{2\pi}\sigma}exp(-\frac{(x-\mu)^2}{2\sigma^2})$"    pl.text(1.5,0.4,label_f2,fontsize=15,verticalalignment="top"            ,horizontalalignment="left")    pl.show()