Class: Symbolic::Summands

Inherits:
Expression show all
Defined in:
lib/symbolic/summands.rb

Instance Attribute Summary

Attributes inherited from Expression

#numeric, #symbolic

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Expression

#==, add, convert, #initialize, numeric, one, simple?, subtract, unite, unite_numeric, unite_symbolic, #variables

Methods included from Symbolic

#*, #**, #+, #+@, #-, #-@, #/, #coerce, #inspect, #operations

Constructor Details

This class inherits a constructor from Symbolic::Expression

Class Method Details

.factors(factors) ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 17

def factors(factors)
  if factors.symbolic.length == 1 && factors.symbolic.values.first == 1
    new identity_element, factors.symbolic.keys.first => factors.numeric
  else
    new identity_element, Factors.new(1, factors.symbolic) => factors.numeric
  end
end

.identity_element ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 9

def identity_element
  0
end

.operation ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 5

def operation
  '+'
end

.simplify(numeric, symbolic) ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 29

def simplify(numeric, symbolic)
  if symbolic.empty?
    numeric
  elsif numeric == identity_element && symbolic.size == 1
    symbolic.values.first * symbolic.keys.first
  end
end

.simplify_expression!(summands) ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 25

def simplify_expression!(summands)
  summands[1].delete_if {|base, coef| coef == 0 }
end

.summands(summands) ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 13

def summands(summands)
  summands
end

Instance Method Details

#coef_to_string(coef) ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 55

def coef_to_string(coef)
  "#{(coef > 0) ? '+' : '-' }#{ "#{rational_to_string(coef.abs)}*" if coef.abs != 1}"
end

#rational_to_string(numeric) ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 63

def rational_to_string(numeric)
  ((numeric.round == numeric) ? numeric.to_i : numeric.to_f).to_s
end

#remainder_to_string(numeric) ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 59

def remainder_to_string(numeric)
  "#{'+' if numeric > 0}#{numeric}"
end

#reverse ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 51

def reverse
  self.class.new -numeric, Hash[*symbolic.map {|k,v| [k,-v]}.flatten]
end

#to_s ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 44

def to_s
  output = symbolic.map {|base, coef| coef_to_string(coef) + base.to_s }
  output << remainder_to_string(numeric) if numeric != 0
  output[0].sub!(/^\+/, '')
  output.join
end

#value ⇒ Object 



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# File 'lib/symbolic/summands.rb', line 38

def value
  if variables.all? &:value
    symbolic.inject(numeric) {|value, (base, coef)| value + base.value * coef.value }
  end
end