def max list = @alt
      values = self[list]
      values.reduce(0){ |memo,v| (v>memo ? v : memo) }
    end
def max list = @alt
      values = self[list]
      values.reduce(0){ |memo,v| (v>memo ? v : memo) }
    end
Return the max value on the nucleotides in the list (typically rec.alt)