# -*- coding: utf-8 -*-#! python2import numpy as np import matplotlib.pyplot as plt from pylab import mplmpl.rcParams['font.sans-serif'] = ['SimHei'] # 指定默认字体plt.rcParams['axes.unicode_minus']=False #解决负数坐标显示问题 #x的个数决定了样本量x = np.arange(-1,1,0.02) #y为理想函数 y = 2*np.sin(x*2.3)+0.5*x**3#y1为离散的拟合数据y1 = y+0.5*(np.random.rand(len(x))-0.5)z1 = np.polyfit(x, y, 6)# 生成多项式对象p1 = np.poly1d(z1)pp1=p1(x)###################################plt.plot(x,y,color='g',linestyle='-',marker='',label=u'理想曲线') plt.plot(x,y1,color='m',linestyle='',marker='o',label=u'拟合数据')plt.plot(x,pp1,color='b',linestyle='-',marker='.',label=u"拟合曲线") # 把拟合的曲线在这里画出来plt.legend(loc='upper left')plt.show()
