python绘制热力图利用python中的matplotlib中的pyplot包绘制二维热力图

# -*- coding: utf-8 -*- """ Created on Wed Nov 29 11:16:20 2017 @author: sxl """ import numpy as np import matplotlib.pyplot as plt # Read dataset x, y = [], [] for sample in open("F:/Python27/spyder/data01.txt", "r"): xx, yy = sample.split(",") x.append(float(xx)) y.append(float(yy)) x, y = np.array(x), np.array(y) # Perform normalization x = (x - x.mean()) / x.std() # Scatter dataset plt.figure() plt.scatter(x, y, c="g", s=20) plt.show() x0 = np.linspace(-2, 4, 100) # Get regression model under LSE criterion with degree 'deg' def get_model(deg): return lambda input_x=x0: np.polyval(np.polyfit(x, y, deg), input_x) # Get the cost of regression model above under given x, y def get_cost(deg, input_x, input_y): return 0.5 * ((get_model(deg)(input_x) - input_y) ** 2).sum() # Set degrees test_set = (1, 4, 10) for d in test_set: print(get_cost(d, x, y)) # Visualize results plt.scatter(x, y, c="g", s=20) for d in test_set: plt.plot(x0, get_model(d)(), label="degree = {}".format(d)) plt.xlim(-2, 4) plt.ylim(1e5, 8e5) plt.legend() plt.show()