class Integer
Public Instance Methods
digit_count()
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Returns the number of digits in the number
# File lib/more_ruby/integer.rb, line 6 def digit_count self.to_s.size end
signif(num_digits)
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Code taken from www.ruby-forum.com/topic/187036 ; all credit for mechanism goes to Harry Kakueki Method is same as Float#signif
below; dangerous to add to common parent Numeric
?
# File lib/more_ruby/integer.rb, line 12 def signif(num_digits) raise TypeError, "Must call #{__method__} with an Integer" unless num_digits.kind_of?(Integer) raise ArgumentError, "Must call #{__method__} with a positive Integer" if num_digits < 0 # 0 is a special case, but allowed return 0.0 if num_digits == 0 return self if self.digit_count <= num_digits m = (num_digits - 1) - Math.log10(self.abs).floor BigDecimal.new(((self * 10 ** m).round * 10 ** (-1 * m)).to_s).to_s('F').gsub(/\.0*$/,"").to_i end