Class: ORTools::LinearConstraint

Inherits:
Object
  • Object
show all
Defined in:
lib/or_tools/linear_constraint.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(expr, lb, ub) ⇒ LinearConstraint

Returns a new instance of LinearConstraint.



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# File 'lib/or_tools/linear_constraint.rb', line 5

def initialize(expr, lb, ub)
  @expr = expr
  @lb = lb
  @ub = ub
end

Instance Attribute Details

#expr ⇒ Object (readonly)

Returns the value of attribute expr.



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# File 'lib/or_tools/linear_constraint.rb', line 3

def expr
  @expr
end

#lb ⇒ Object (readonly)

Returns the value of attribute lb.



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# File 'lib/or_tools/linear_constraint.rb', line 3

def lb
  @lb
end

#ub ⇒ Object (readonly)

Returns the value of attribute ub.



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# File 'lib/or_tools/linear_constraint.rb', line 3

def ub
  @ub
end

Instance Method Details

#extract(solver) ⇒ Object 



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# File 'lib/or_tools/linear_constraint.rb', line 31

def extract(solver)
  coeffs = @expr.coeffs
  constant = coeffs.delete(OFFSET_KEY) || 0.0
  lb = -solver.infinity
  ub = solver.infinity
  if @lb > -Float::INFINITY
    lb = @lb - constant
  end
  if @ub < Float::INFINITY
    ub = @ub - constant
  end

  constraint = solver.constraint(lb, ub)
  coeffs.each do |v, c|
    constraint.set_coefficient(v, c.to_f)
  end
  constraint
end

#inspect ⇒ Object 



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# File 'lib/or_tools/linear_constraint.rb', line 27

def inspect
  "#<#{self.class.name} #{to_s}>"
end

#to_s ⇒ Object 



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# File 'lib/or_tools/linear_constraint.rb', line 11

def to_s
  if @lb > -Float::INFINITY && @ub < Float::INFINITY
    if @lb == @ub
      "#{@expr} == #{@lb}"
    else
      "#{@lb} <= #{@expr} <= #{@ub}"
    end
  elsif @lb > -Float::INFINITY
    "#{@expr} >= #{@lb}"
  elsif @ub < Float::INFINITY
    "#{@expr} <= #{@ub}"
  else
    "Trivial inequality (always true)"
  end
end