Python SymPy Permutation.get_precedence_matrix()用法及代码示例

Permutation.get_precedence_matrix()：get_precedence_matrix()是一个sympy Python库函数，可通过计算两者之间的优先级距离来计算参数中置换的优先级矩阵。

p和q代表n个工作。优先级度量标准计数为no。在p和q中，作业n在作业n之前通常是作业m的次数。这是一个交换矩阵。

用法：

sympy.combinatorics.permutations.Permutation.get_precedence_matrix()

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]])