Coverage for local/lib/python2.7/site-packages/sage/combinat/rigged_configurations/bij_type_A2_even.py : 90%

r""" 

Bijection classes for type `A_{2n}^{(2)}`. 

Part of the (internal) classes which runs the bijection between rigged 

configurations and KR tableaux of type `A_{2n}^{(2)}`. 

AUTHORS: 

- Travis Scrimshaw (2012-12-21): Initial version 

TESTS:: 

sage: KRT = crystals.TensorProductOfKirillovReshetikhinTableaux(['A', 4, 2], [[2, 1]]) 

sage: from sage.combinat.rigged_configurations.bij_type_A2_even import KRTToRCBijectionTypeA2Even 

sage: bijection = KRTToRCBijectionTypeA2Even(KRT(pathlist=[[-1,2]])) 

sage: TestSuite(bijection).run() 

sage: RC = RiggedConfigurations(['A', 4, 2], [[2, 1]]) 

sage: from sage.combinat.rigged_configurations.bij_type_A2_even import RCToKRTBijectionTypeA2Even 

sage: bijection = RCToKRTBijectionTypeA2Even(RC(partition_list=[[],[]])) 

sage: TestSuite(bijection).run() 

""" 

#***************************************************************************** 

# Copyright (C) 2012 Travis Scrimshaw <tscrim@ucdavis.edu> 

# 

# Distributed under the terms of the GNU General Public License (GPL) 

# 

# This code is distributed in the hope that it will be useful, 

# but WITHOUT ANY WARRANTY; without even the implied warranty of 

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 

# General Public License for more details. 

# 

# The full text of the GPL is available at: 

# 

# http://www.gnu.org/licenses/ 

#***************************************************************************** 

from sage.combinat.rigged_configurations.bij_type_A import KRTToRCBijectionTypeA 

from sage.combinat.rigged_configurations.bij_type_C import KRTToRCBijectionTypeC 

from sage.combinat.rigged_configurations.bij_type_C import RCToKRTBijectionTypeC 

class KRTToRCBijectionTypeA2Even(KRTToRCBijectionTypeC): 

r""" 

Specific implementation of the bijection from KR tableaux to rigged 

configurations for type `A_{2n}^{(2)}`. 

This inherits from type `C_n^{(1)}` because we use the same methods in 

some places. 

""" 

def next_state(self, val): 

r""" 

Build the next state for type `A_{2n}^{(2)}`. 

TESTS:: 

sage: KRT = crystals.TensorProductOfKirillovReshetikhinTableaux(['A', 4, 2], [[2,1]]) 

sage: from sage.combinat.rigged_configurations.bij_type_A2_even import KRTToRCBijectionTypeA2Even 

sage: bijection = KRTToRCBijectionTypeA2Even(KRT(pathlist=[[-1,-2]])) 

sage: bijection.cur_path.insert(0, []) 

sage: bijection.cur_dims.insert(0, [0, 1]) 

sage: bijection.cur_path[0].insert(0, [-2]) 

sage: bijection.next_state(-2) 

""" 

# Note that we must subtract 1 from n to match the indices. 

n = self.n 

tableau_height = len(self.cur_path[0]) - 1 

# If it is a regular value, we follow the A_n rules 

if val != 'E' and val > 0: 

KRTToRCBijectionTypeA.next_state(self, val) 

return 

case_S = [None] * n 

if val == 'E': 

pos_val = n 

max_width = self.ret_rig_con[n-1].insert_cell(0) 

else: 

pos_val = -val 

# Always add a cell to the first singular value in the first 

# tableau we are updating. 

if len(self.ret_rig_con[pos_val - 1]) > 0: 

max_width = self.ret_rig_con[pos_val - 1][0] 

else: 

max_width = 1 

# Add cells similar to type A_n but we move to the right until we 

# reach the value of n 

for a in range(pos_val - 1, n): 

max_width = self.ret_rig_con[a].insert_cell(max_width) 

case_S[a] = max_width 

# Special case for n 

self._insert_cell_case_S(self.ret_rig_con[n-1]) 

# Now go back following the regular C_n (ish) rules 

for a in reversed(range(tableau_height, n-1)): 

if case_S[a] == max_width: 

self._insert_cell_case_S(self.ret_rig_con[a]) 

else: 

max_width = self.ret_rig_con[a].insert_cell(max_width) 

self._update_vacancy_nums(a + 1) 

self._update_partition_values(a + 1) 

# Update the final rigged partitions 

if tableau_height < n: 

self._update_vacancy_nums(tableau_height) 

self._update_partition_values(tableau_height) 

if pos_val <= tableau_height: 

for a in range(pos_val-1, tableau_height): 

self._update_vacancy_nums(a) 

self._update_partition_values(a) 

if pos_val > 1: 

self._update_vacancy_nums(pos_val - 2) 

self._update_partition_values(pos_val - 2) 

elif tableau_height > 0: 

self._update_vacancy_nums(tableau_height - 1) 

self._update_partition_values(tableau_height - 1) 

class RCToKRTBijectionTypeA2Even(RCToKRTBijectionTypeC): 

r""" 

Specific implementation of the bijection from rigged configurations to 

tensor products of KR tableaux for type `A_{2n}^{(2)}`. 

""" 

def next_state(self, height): 

r""" 

Build the next state for type `A_{2n}^{(2)}`. 

TESTS:: 

sage: RC = RiggedConfigurations(['A', 4, 2], [[2,1]]) 

sage: from sage.combinat.rigged_configurations.bij_type_A2_even import RCToKRTBijectionTypeA2Even 

sage: bijection = RCToKRTBijectionTypeA2Even(RC(partition_list=[[2],[2,2]])) 

sage: bijection.next_state(2) 

-1 

""" 

height -= 1 # indexing 

n = self.n 

ell = [None] * (2*n) 

case_S = [False] * n 

b = None 

# Calculate the rank and ell values 

last_size = 0 

for a in range(height, n): 

ell[a] = self._find_singular_string(self.cur_partitions[a], last_size) 

if ell[a] is None: 

b = a + 1 

break 

else: 

last_size = self.cur_partitions[a][ell[a]] 

if b is None and last_size == 1: 

b = 'E' 

# This is a slight hack since remove_cell() will just delete the 

# appropriate row 

case_S[n-1] = True 

if b is None: 

# Now go back 

ell[2*n-1] = ell[n-1] 

case_S[n-1] = True 

for a in reversed(range(n-1)): 

if a >= height and self.cur_partitions[a][ell[a]] == last_size: 

ell[n+a] = ell[a] 

case_S[a] = True 

else: 

ell[n+a] = self._find_singular_string(self.cur_partitions[a], last_size) 

if ell[n + a] is None: 

b = -(a + 2) 

break 

else: 

last_size = self.cur_partitions[a][ell[n + a]] 

if b is None: 

b = -1 

# Determine the new rigged configuration by removing boxes from the 

# selected string and then making the new string singular 

if case_S[0]: 

row_num = self.cur_partitions[0].remove_cell(ell[0], 2) 

row_num_bar = None 

else: 

row_num = self.cur_partitions[0].remove_cell(ell[0]) 

row_num_bar = self.cur_partitions[0].remove_cell(ell[n]) 

for a in range(1, n): 

if case_S[a]: 

row_num_next = self.cur_partitions[a].remove_cell(ell[a], 2) 

row_num_bar_next = None 

else: 

row_num_next = self.cur_partitions[a].remove_cell(ell[a]) 

row_num_bar_next = self.cur_partitions[a].remove_cell(ell[n+a]) 

self._update_vacancy_numbers(a - 1) 

if row_num is not None: 

self.cur_partitions[a-1].rigging[row_num] = self.cur_partitions[a-1].vacancy_numbers[row_num] 

if row_num_bar is not None: 

self.cur_partitions[a-1].rigging[row_num_bar] = self.cur_partitions[a-1].vacancy_numbers[row_num_bar] 

row_num = row_num_next 

row_num_bar = row_num_bar_next 

self._update_vacancy_numbers(n - 1) 

if row_num is not None: 

self.cur_partitions[n-1].rigging[row_num] = self.cur_partitions[n-1].vacancy_numbers[row_num] 

if row_num_bar is not None: 

self.cur_partitions[n-1].rigging[row_num_bar] = self.cur_partitions[n-1].vacancy_numbers[row_num_bar] 

return(b)