Python| SymPy Permutation.get_precedence_matrix() 方法

Permutation.get_precedence_matrix() ：get_precedence_matrix()是一个 sympy Python库函数，它通过计算两者之间的优先距离来计算参数中排列的优先矩阵。

p 和 q 代表 n 个工作。优先级度量计数。在 p 和 q 中，作业 n 之前有作业 m 的次数。这是一个交换矩阵。

Syntax :
sympy.combinatorics.permutations.Permutation.get_precedence_matrix()

Return :
calculates the precedence matrix for the permutation

代码 #1：get_precedence_matrix() 示例

# Python code explaining
# SymPy.Permutation.get_precedence_matrix()
  
# importing SymPy libraries
from sympy.combinatorics.partitions import Partition
from sympy.combinatorics.permutations import Permutation
  
# Using from 
# sympy.combinatorics.permutations.Permutation.get_precedence_matrix() method 
  
# creating Permutation
a = Permutation([2, 0, 3, 1, 5, 4])
  
b = Permutation([3, 1, 2, 5, 4, 0])
  
print ("a - get_precedence_matrix : \n", a.get_precedence_matrix())
print ("b - get_precedence_matrix : \n", b.get_precedence_matrix())

输出 ：

a – get_precedence_matrix :
Matrix([[0, 1, 0, 1, 1, 1],
[0, 0, 0, 0, 1, 1],
[1, 1, 0, 1, 1, 1],
[0, 1, 0, 0, 1, 1],
[0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 1, 0]])

b – get_precedence_matrix :
Matrix([[0, 0, 0, 0, 0, 0],
[1, 0, 1, 0, 1, 1],
[1, 0, 0, 0, 1, 1],
[1, 1, 1, 0, 1, 1],
[1, 0, 0, 0, 0, 0],
[1, 0, 0, 0, 1, 0]])

代码 #2：get_precedence_matrix() 示例– 2D 排列

# Python code explaining
# SymPy.Permutation.get_precedence_matrix()
  
# importing SymPy libraries
from sympy.combinatorics.partitions import Partition
from sympy.combinatorics.permutations import Permutation
  
# Using from 
# sympy.combinatorics.permutations.Permutation.get_precedence_matrix() method 
  
# creating Permutation
a = Permutation([[2, 4, 0], 
                 [7, 1, 3],
                 [8, 5, 6]])
  
b = Permutation([[8, 4, 0], 
                 [2, 7, 0],
                 [1, 6, 7]])
      
print ("a get_precedence_matrix : \n", a.get_precedence_matrix())
  
print ("\nb get_precedence_matrix : \n", b.get_precedence_matrix())

输出 ：

a get_precedence_matrix :
Matrix([[0, 1, 0, 0, 0, 1, 1, 0, 1],
[0, 0, 0, 0, 0, 1, 0, 0, 0],
[1, 1, 0, 1, 1, 1, 1, 1, 1],
[1, 1, 0, 0, 1, 1, 1, 1, 1],
[1, 1, 0, 0, 0, 1, 1, 1, 1],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 1, 0, 0, 0, 1, 0, 0, 1],
[1, 1, 0, 0, 0, 1, 1, 0, 1],
[0, 1, 0, 0, 0, 1, 0, 0, 0]])

b get_precedence_matrix :
Matrix([[0, 0, 0, 0, 1, 0, 0, 0, 0],
[1, 0, 1, 1, 1, 1, 0, 1, 0],
[1, 0, 0, 0, 1, 1, 0, 1, 0],
[1, 0, 1, 0, 1, 1, 0, 1, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[1, 0, 0, 0, 1, 0, 0, 1, 0],
[1, 1, 1, 1, 1, 1, 0, 1, 0],
[1, 0, 0, 0, 1, 0, 0, 0, 0],
[1, 1, 1, 1, 1, 1, 1, 1, 0]])