Opened 8 years ago

Closed 7 years ago

# Shouldn't the attacking_pairs method live in Partitions, not in Tableaux?

Reported by: Owned by: darij sage-combinat minor sage-duplicate/invalid/wontfix combinatorics tableaux, partitions, combinat sage-combinat, tscrim, chrisjamesberg N/A

### Description

I was scrolling through sage/combinat/tableau.py and found this method of the Tableau class:

```    def attacking_pairs(self):
"""
Returns a list of the attacking pairs of self. An pair of cells (c,
d) is said to be attacking if one of the following conditions
hold:

1. c and d lie in the same row with c to the west of d

2. c is in the row immediately to the south of d and c
lies strictly east of d.

EXAMPLES::

sage: t = Tableau([[1,2,3],[2,5]])
sage: t.attacking_pairs()
[((0, 0), (0, 1)),
((0, 0), (0, 2)),
((0, 1), (0, 2)),
((1, 0), (1, 1)),
((1, 1), (0, 0))]
"""
attacking_pairs = []
for i in range(len(self)):
for j in range(len(self[i])):
#c is in position (i,j)
#Find the d that satisfy condition 1
for k in range(j+1,len(self[i])):
attacking_pairs.append( ((i,j),(i,k)) )

#Find the d that satisfy condition 2
if i == 0:
continue
for k in range(j):
attacking_pairs.append( ((i,j),(i-1,k)) )

return attacking_pairs
```

I see nothing about this method that actually uses the entries of the tableau, as opposed to just its shape. As the method is never used (or at least grep "attacking_pairs" -r * doesn't find it anywhere outside its own definition), it shouldn't be hard to just move it, right?

### comment:1 Changed 8 years ago by darij

• Component changed from PLEASE CHANGE to combinatorics
• Owner changed from tbd to sage-combinat

### comment:2 Changed 8 years ago by jdemeyer

• Milestone changed from sage-5.11 to sage-5.12

### comment:3 Changed 7 years ago by tscrim

• Cc chrisjamesberg added

I agree (somehow I had missed this e-mail). I'm cc-ing Chris Berg to see if he has an opinion on this.

### comment:4 Changed 7 years ago by darij

Oops, I forgot about this ticket. Everything I wanted to do about this is done and merged already in #15327. Sorry for the misdirection.

### comment:5 Changed 7 years ago by darij

• Status changed from new to needs_review

### comment:6 Changed 7 years ago by darij

• Status changed from needs_review to positive_review

### comment:7 Changed 7 years ago by tscrim

• Milestone changed from sage-6.1 to sage-duplicate/invalid/wontfix

### comment:8 Changed 7 years ago by vbraun

• Resolution set to duplicate
• Status changed from positive_review to closed
Note: See TracTickets for help on using tickets.