如果对象函数是
如何在python中编码？我已编码正常的：
import numpy as np
import scipy as sp
from scipy.optimize import leastsq
import pylab as pl
m = 9 #the degree of the polynomial
def real_func(x):
return np.sin(2*np.pi*x) #sin(2 pi x)
def fake_func(p, x):
f = np.poly1d(p) #polynomial
return f(x)
def residuals(p, y, x):
return y - fake_func(p, x)
#randomly choose 9 points as x
x = np.linspace(0, 1, 9)
x_show = np.linspace(0, 1, 1000)
y0 = real_func(x)
#add normalize noise
y1 = [np.random.normal(0, 0.1) + y for y in y0]
p0 = np.random.randn(m)
plsq = leastsq(residuals, p0, args=(y1, x))
print 'Fitting Parameters ：', plsq[0]
pl.plot(x_show, real_func(x_show), label='real')
pl.plot(x_show, fake_func(plsq[0], x_show), label='fitted curve')
pl.plot(x, y1, 'bo', label='with noise')
pl.legend()
pl.show()
1 回答
由于惩罚项也只是二次方，你可以将它与错误的方形叠加在一起，并使用权重1表示数据，lambda表示惩罚行 .
如果你不想自己编码，scipy.optimize.curvefit会加权最小二乘法 .