nn88 - 経済統計練習帳

import math
 
def f(xx):
    f1=1+math.exp(-1*xx)
    return 1/f1
 
def g(ax):
    g1=0
    for i in range(5):
        y1=ax[0]
        for j in range(2):
            y1=y1+ax[j+1]*x[i][j]
            ys[i]=f(y1)
        g1=g1+(y[i]-ys[i])*(y[i]-ys[i])
    return g1
 
def dg(m):
    h=0.01
    g1=g(a)
    ax=a
    ax[m]=a[m]+h
    g2=g(ax)
    gg= (g1 - g2)/h
    return gg
 
y=[0,0,0,1,1]
x=[[2,3],[4,5],[5,2],[1,7],[2,2]]
a=[-2,0.7,0.5]
ys=[0,0,0,0,0]
 
de=[0,0,0]
 
for i in range(3):
    de[i]=dg(i)
 
print(de)