Permutation.descents() : descents() is a sympy Python library function that returns the position of descents in the permutation. Descents are the elements where a[i] > a[i+1]
Syntax : sympy.combinatorics.permutations.Permutation.descents()
Return : position of descents in the permutation
Code #1 : descents() Example
# Python code explaining # SymPy.descents() # importing SymPy libraries from sympy.combinatorics.partitions import Partition from sympy.combinatorics.permutations import Permutation # Using from sympy.combinatorics.permutations.Permutation.descents() method # creating Permutation a = Permutation([[2, 0], [3, 1]]) b = Permutation([1, 3, 5, 4, 2, 0]) print ("Permutation a - descents form : ", a.descents()) print ("Permutation b - descents form : ", b.descents()) |
Output :
Permutation a – descents form : [1]
Permutation b – descents form : [2, 3, 4]
Code #2 : descents() Example – 2D Permutation
# Python code explaining # SymPy.descents() # importing SymPy libraries from sympy.combinatorics.partitions import Partition from sympy.combinatorics.permutations import Permutation # Using from sympy.combinatorics.permutations.Permutation.descents() method # creating Permutation a = Permutation([[2, 4, 0], [3, 1, 2], [1, 5, 6]]) print ("Permutation a - descents form : ", a.descents()) |
Output :
Permutation a – descents form : [0, 3, 5]
