class Object
Public Instance Methods
ncr(n, r)
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# File lib/probaberry/counting.rb, line 22 def ncr n, r raise ArgumentError, "r = #{r} is outside 0..#{n}" if r < 0 or r > n n.choose r end
nice(n, p=3)
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# File lib/probaberry/nice.rb, line 1 def nice n, p=3 return n unless n.kind_of? Numeric i = n.to_i f = ((n - i).round(p).to_s)[2..-1] i = i.to_s.reverse.gsub(/...(?=.)/, '\& ').reverse "#{i}.#{f}" end
npr(n, r)
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# File lib/probaberry/counting.rb, line 27 def npr n, r raise ArgumentError, "r = #{r} is outside 0..#{n}" if r < 0 or r > n n.!.fdiv((n - r).!).to_i end