(3)网格化转二维数组
x = np.linspace(train[:,0].min(),train[:,0].max(),300) #一维300个 y = np.linspace(train[:,1].min(),train[:,1].max(),300) #一维300个 #将一维数据x y网格化为二维数组 300x300 xx,yy = np.meshgrid(x,y) # ravel扁平化90000 # np.c_是按行连接两个矩阵，就是把两矩阵左右相加，要求行数相等，类似于pandas中的merge() X_test = np.c_[xx.ravel(),yy.ravel()] #输出 X_test array([[4.3 , 2. ], [4.31204013, 2. ], [4.32408027, 2. ], ..., [7.87591973, 4.4 ], [7.88795987, 4.4 ], [7.9 , 4.4 ]])