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"""
The Sponge Roll Problem with Column Generation for the PuLP Modeller
Authors: Antony Phillips, Dr Stuart Mitchell 2008
"""
# Import Column Generation functions
from CG import *
# The roll data is created
rollData = {#Length Demand SalePrice
"5": [150, 0.25],
"7": [200, 0.33],
"9": [300, 0.40]}
# The boolean variable morePatterns is set to True to test for more patterns
morePatterns = True
# A list of starting patterns is created
patternslist = [[4,0,0],[0,2,0],[0,0,2]]
# The starting patterns are instantiated with the Pattern class
Patterns = []
for i in patternslist:
Patterns += [Pattern("P" + str(len(Patterns)), i)]
# This loop will be repeated until morePatterns is set to False
while morePatterns == True:
# Solve the problem as a Relaxed LP
duals = masterSolve(Patterns, rollData)
# Find another pattern
Patterns, morePatterns = subSolve(Patterns, duals)
# Re-solve as an Integer Problem
solution, varsdict = masterSolve(Patterns, rollData, relax = False)
# Display Solution
for i,j in list(varsdict.items()):
print(i, "=", j)
print("objective = ", solution)
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