31 lines
716 B
Ruby
31 lines
716 B
Ruby
#
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# BigDecimal <-> Rational
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#
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class BigDecimal
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# Convert BigDecimal to Rational
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def to_r
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sign,digits,base,power = self.to_parts
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numerator = sign*digits.to_i
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denomi_power = power - digits.size # base is always 10
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if denomi_power < 0
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denominator = base ** (-denomi_power)
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else
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denominator = base ** denomi_power
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end
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Rational.new(numerator,denominator)
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end
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end
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class Rational
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# Convert Rational to BigDecimal
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# to_d returns an array [quotient,residue]
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def to_d(nFig=0)
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num = self.numerator.to_s
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if nFig<=0
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nFig = BigDecimal.double_fig*2+1
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end
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BigDecimal.new(num).div(self.denominator,nFig)
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end
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end
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