def row(index)
      pos = @index.index(index)
      arr = @data.map{|column| column[pos]}
      Mikon::Row.new(@labels, arr, index)
    end
def row(index)
      pos = @index.index(index)
      arr = @data.map{|column| column[pos]}
      Mikon::Row.new(@labels, arr, index)
    end
Access row using index