Question

以下是用python 3.6编写的程序

import numpy as np    
def linmodel(x, y, alp, ep):
    x = np.array(x)
    y = np.array(y)
    (m, n) = x.shape
    yh = np.zeros((m,1))
    J = []
    w = np.array(np.random.rand(n+1, 1))
    for i in range(m):
        yh[i][0] = np.matmul(x[i],w[1:])
        yh[i][0] += w[0]
    yh = np.array(yh)
    J.append(0.5/m*sum((y-yh)**2))
    err = 1
    iter = 1
    while(err>ep):
        dj = np.zeros((n+1,1))
        dj = np.array(dj)
        pred_err = yh - y
        dj[0][0] = sum(pred_err)/m
        for j in range(1,n+1):
            dj[j][0] = sum(pred_err * x[:][j-1])/m
        w = w - alp*dj
        for i in range(m):
            yh[i][0] = np.matmul(x[i],w[1:])
            yh[i][0] += w[0]
        iter = iter+1
        J.append(0.5/m*sum((y-yh)**2))
        err = np.linalg.norm(alp*dj, 2)    
T = np.array(range(-341,80))
T = T[::-20]

Talp = [6.47,6.36,6.24,6.12,6.00,5.86,5.72,5.58,5.43,5.28,5.09,4.91,4.72,4.52,4.3,4.08,3.83,3.58,3.33,3.07,2.76,2.45]
Talp = np.array(Talp)[np.newaxis]
Talp = Talp*(1.0E-6)
T = np.array(T)[np.newaxis]
x = T.T
y = Talp.T    
alp = 0.1
ep = 1.0E-5    
linmodel(x, y, alp, ep)

当我运行该程序时，出现运行时错误，这对我完全没有意义。

RuntimeWarning: overflow encountered in square
  J.append(0.5/m*sum((y-yh)**2))
RuntimeWarning: overflow encountered in multiply
  dj[j][0] = sum(pred_err * x[:][j-1])/m
RuntimeWarning: invalid value encountered in add
  dj[j][0] = sum(pred_err * x[:][j-1])/m

我== 此错误的原因是什么？我该如何纠正？

Python：RuntimeWarning：在正方形中遇到溢出

0 个答案: