text: from matplotlib.pyplot import show
  from numpy import *
  
  from bases.cartesian import Cartesian
  from bases.oblique_coord import ObliqueCoord
  
  a = array([5, 1])
  b = array([2, 6])
  cartesian = Cartesian(-2, 15)
  oblique = ObliqueCoord(cartesian, a, b, "red")
  oblique.draw_basis()
  
  print("[a,b].T")
  print(oblique.G)
  
  print("\n坐标乘, 结果是向量")
  print(multiply(a, b))
  print(a * b)
  
  print("\n內积，点乘，矩阵乘，结果是标量")
  print(dot(a, b))
  print(inner(a, b))
  print(a @ b)
  
  print("\n叉积，向量乘，结果是向量，但只有一个长度读数。方向是垂直于a,b")
  print(cross(a, b))
  
  print("\n外积，并矢，张量乘，结果是矩阵，张量")
  print(outer(a, b))
  
  print("\n度量张量")
  print(oblique.metrics_tensor)
  show()
  