Ribbon Shaped Tableaux

class sage.combinat.ribbon_shaped_tableau.RibbonShapedTableau(parent, t)

Bases: sage.combinat.skew_tableau.SkewTableau

A ribbon.

A ribbon is a skew tableau that does not contain a 2 \times 2 box. A ribbon is given by a list of the rows from top to bottom.

EXAMPLES:

sage: x = RibbonShapedTableau([[None, None, None, 2, 3], [None, 1, 4, 5], [3, 2]]); x
[[None, None, None, 2, 3], [None, 1, 4, 5], [3, 2]]
sage: x.pp()
  .  .  .  2  3
  .  1  4  5
  3  2
sage: x.shape()
[5, 4, 2] / [3, 1]

The entries labeled by None correspond to the inner partition. Using None is optional, the entries will be shifted accordingly.

sage: x = RibbonShapedTableau([[2,3],[1,4,5],[3,2]]); x.pp()
  .  .  .  2  3
  .  1  4  5
  3  2
evaluation()

Return the evaluation of the word from ribbon.

EXAMPLES:

sage: RibbonShapedTableau([[1,2],[3,4]]).evaluation()
[1, 1, 1, 1]
height()

Return the height of self.

The height is given by the number of rows in the outer partition.

EXAMPLES:

sage: RibbonShapedTableau([[2,3],[1,4,5]]).height()
2
spin()

Return the spin of self.

EXAMPLES:

sage: RibbonShapedTableau([[2,3],[1,4,5]]).spin()
1/2
to_permutation()

Returns the permutation corresponding to the ribbon tableau.

EXAMPLES:

sage: r = RibbonShapedTableau([[1], [2,3], [4, 5, 6]])
sage: r.to_permutation()
[4, 5, 6, 2, 3, 1]
to_skew_tableau()

This is deprecated in trac ticket #14101 since RibbonShapedTableau inherits from SkewTableau.

EXAMPLES:

sage: RibbonShapedTableau([[2,3],[1,4,5]]).to_skew_tableau()
doctest:...: DeprecationWarning: this method is deprecated since ribbon shaped tableaux are skew partitions
See http://trac.sagemath.org/14101 for details.
[[None, None, 2, 3], [1, 4, 5]]
width()

Return the width of the ribbon.

This is given by the length of the longest row in the outer partition.

EXAMPLES:

sage: RibbonShapedTableau([[2,3],[1,4,5]]).width()
4
sage: RibbonShapedTableau([]).width()
0
class sage.combinat.ribbon_shaped_tableau.StandardRibbonShapedTableaux(category=None)

Bases: sage.combinat.skew_tableau.StandardSkewTableaux

The set of all standard ribbon shaped tableaux.

INPUT:

  • shape – (optional) the composition shape of the rows
Element

alias of RibbonShapedTableau

from_permutation(p)

Return a standard ribbon of size len(p) from a permutation p. The lengths of each row are given by the distance between the descents of the permutation p.

EXAMPLES:

sage: import sage.combinat.ribbon_shaped_tableau as rst
sage: [StandardRibbonShapedTableaux().from_permutation(p) for p in Permutations(3)]
[[[1, 2, 3]],
 [[None, 2], [1, 3]],
 [[1, 3], [2]],
 [[None, 1], [2, 3]],
 [[1, 2], [3]],
 [[1], [2], [3]]]
from_shape_and_word(shape, word)

Return the ribbon corresponding to the given ribbon shape and word.

EXAMPLES:

sage: StandardRibbonShapedTableaux().from_shape_and_word([2,3],[1,2,3,4,5])
[[None, None, 1, 2], [3, 4, 5]]
global_options(*get_value, **set_value)

Sets the global options for elements of the tableau, skew_tableau, and tableau tuple classes. The defaults are for tableau to be displayed as a list, latexed as a Young diagram using the English convention.

OPTIONS:

  • ascii_art – (default: repr) Controls the ascii art output for tableaux
    • compact – minimal length ascii art
    • repr – display using the diagram string representation
    • table – display as a table
  • convention – (default: English) Sets the convention used for displaying tableaux and partitions
    • English – use the English convention
    • French – use the French convention
  • display – (default: list) Controls the way in which tableaux are printed
    • array – alias for diagram
    • compact – minimal length string representation
    • diagram – display as Young diagram (similar to pp()
    • ferrers_diagram – alias for diagram
    • list – print tableaux as lists
    • young_diagram – alias for diagram
  • latex – (default: diagram) Controls the way in which tableaux are latexed
    • array – alias for diagram
    • diagram – as a Young diagram
    • ferrers_diagram – alias for diagram
    • list – as a list
    • young_diagram – alias for diagram
  • notation – alternative name for convention

Note

Changing the convention for tableaux also changes the convention for partitions.

If no parameters are set, then the function returns a copy of the options dictionary.

EXAMPLES:

sage: T = Tableau([[1,2,3],[4,5]])
sage: T
[[1, 2, 3], [4, 5]]
sage: Tableaux.global_options(display="array")
sage: T
  1  2  3
  4  5
sage: Tableaux.global_options(convention="french")
sage: T
  4  5
  1  2  3

Changing the convention for tableaux also changes the convention for partitions and vice versa:

sage: P = Partition([3,3,1])
sage: print P.ferrers_diagram()
*
***
***
sage: Partitions.global_options(convention="english")
sage: print P.ferrers_diagram()
***
***
*
sage: T
  1  2  3
  4  5

The ASCII art can also be changed:

sage: t = Tableau([[1,2,3],[4,5]])
sage: ascii_art(t)
  1  2  3
  4  5
sage: Tableaux.global_options(ascii_art="normal")
sage: ascii_art(t)
+---+---+
| 4 | 5 |
+---+---+---+
| 1 | 2 | 3 |
+---+---+---+
sage: Tableaux.global_options(ascii_art="compact")
sage: ascii_art(t)
|4|5|
|1|2|3|
sage: Tableaux.global_options.reset()

See GlobalOptions for more features of these options.

class sage.combinat.ribbon_shaped_tableau.StandardRibbonShapedTableaux_shape(shape)

Bases: sage.combinat.ribbon_shaped_tableau.StandardRibbonShapedTableaux

Class of standard ribbon tableaux of ribbon shape shape.

EXAMPLES:

sage: StandardRibbonShapedTableaux([2,2])
Standard ribbon tableaux of shape [2, 2]
sage: StandardRibbonShapedTableaux([2,2]).first()
[[None, 2, 4], [1, 3]]
sage: StandardRibbonShapedTableaux([2,2]).last()
[[None, 1, 2], [3, 4]]
sage: StandardRibbonShapedTableaux([2,2]).cardinality()
5
sage: StandardRibbonShapedTableaux([2,2]).list()
[[[None, 2, 4], [1, 3]],
 [[None, 2, 3], [1, 4]],
 [[None, 1, 4], [2, 3]],
 [[None, 1, 3], [2, 4]],
 [[None, 1, 2], [3, 4]]]
sage: StandardRibbonShapedTableaux([3,2,2]).cardinality()
155
first()

Return the first standard ribbon of self.

EXAMPLES:

sage: StandardRibbonShapedTableaux([2,2]).first()
[[None, 2, 4], [1, 3]]
last()

Return the last standard ribbon of self.

EXAMPLES:

sage: StandardRibbonShapedTableaux([2,2]).last()
[[None, 1, 2], [3, 4]]

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