import numpy as np
from numpy import mat
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D # 画三维图
if __name__ == "__main__":
# 1 获得x,y数据# ##########
X = np.array([[4000, 25], [8000, 30], [5000, 28], [7500, 33], [12000, 40]])
Y = np.array([20000, 70000, 35000, 50000, 85000])
# 2 矩阵形式转换X, Y
Y_mat = mat(Y).T
X_temp = np.ones((5, 3))
X_temp[:, 0] = X[:, 0]
X_temp[:, 1] = X[:, 1]
#print(X_temp)
X_mat = mat(X_temp)
# print(X_mat)
# 3 利用解析法 p = (X^TX)^-1 X^T Y
pamaters = (((X_mat.T) * X_mat).I) * X_mat.T * Y_mat
#print(pamaters)
# 4 显示
fig1 = plt.figure()
ax1 = Axes3D(fig1)
x = X[:, 0]
y = X[:, 1]
z = Y
Z = X_mat * pamaters
#print(Z)
n = list(map(int, Z[:, 0])) # Z中的数的位数超出范围
#print(n)
ax1.scatter3D(x, y, z, c='blue')
ax1.plot3D(x, y, n, c='red')
plt.title("贷款额度预测图") # 设置图表标题
plt.xlabel("工资") # 设置x坐标轴标签
plt.ylabel("年龄") # 设置y坐标轴标签
ax1.set_zlabel("额度")# 设置z坐标标签
plt.rcParams['font.sans-serif'] = ['Kaiti'] # 用来正常显示中文(黑体)常用字体包括: Kaiti-楷体; FangSong-仿宋; Microsoft YaHei-微软雅黑
plt.rcParams['axes.unicode_minus'] = False # 用来正常显示负号
plt.show()
a = eval(input("请输入工资:"))
b = eval(input("请输入年龄: "))
s = np.array([[a, b]])
# print(s)
s_temp = np.ones((1, 3))
s_temp[:, 0] = s[:, 0]
s_temp[:, 1] = s[:, 1]
#print(s_temp)
s_mat = mat(s_temp)
m = s_mat * pamaters
print("贷款额度为:", m)