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path: root/ext/bigdecimal/lib/bigdecimal/util.rb
blob: d9b7ae31317734a957616bb11317081ebd10e854 (plain)
 ```1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 ``` ``````# # BigDecimal utility library. # ---------------------------------------------------------------------- # Contents: # # String# # to_d ... to BigDecimal # # Float# # to_d ... to BigDecimal # # BigDecimal# # to_digits ... to xxxxx.yyyy form digit string(not 0.zzzE?? form). # to_r ... to Rational # # Rational# # to_d ... to BigDecimal # # ---------------------------------------------------------------------- # class Float < Numeric def to_d BigFloat::new(selt.to_s) end end class String def to_d BigDecimal::new(self) end end class BigDecimal < Numeric # to "nnnnnn.mmm" form digit string def to_digits if self.nan? || self.infinite? self.to_s else s,i,y,z = self.fix.split s,f,y,z = self.frac.split if s > 0 s = "" else s = "-" end s + i + "." + f end end # Convert BigDecimal to Rational def to_r sign,digits,base,power = self.split numerator = sign*digits.to_i denomi_power = power - digits.size # base is always 10 if denomi_power < 0 denominator = base ** (-denomi_power) else denominator = base ** denomi_power end Rational(numerator,denominator) end end class Rational < Numeric # Convert Rational to BigDecimal # to_d returns an array [quotient,residue] def to_d(nFig=0) num = self.numerator.to_s if nFig<=0 nFig = BigDecimal.double_fig*2+1 end BigDecimal.new(num).div(self.denominator,nFig) end end ``````