Python | SymPy Permutation.get_precedence_distance() method

0 0 1 minute read

Permutation.get_precedence_distance() : get_precedence_distance() is a sympy Python library function that calculates the precedence distance between two permutations.

p and q represent n jobs. The precedence metric counts the no. of times a job n is preceded by job m in both p and q. This is a commutative matrix.

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

Return :
precedence distance between two permutations

Code #1 : get_precedence_distance() Example

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

Output :

a – get_precedence_distance form b: 6
b – get_precedence_distance form c: 9

Code #2 : get_precedence_distance() Example – 2D Permutation

# Python code explaining 
# SymPy.Permutation.get_precedence_distance() 
  
# importing SymPy libraries 
from sympy.combinatorics.partitions import Partition 
from sympy.combinatorics.permutations import Permutation 
  
# Using from  
# sympy.combinatorics.permutations.Permutation.get_precedence_distance() 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_distance form b : ", a.get_precedence_distance(b)) 