ruby Matrix 输出 格式化

 require 'matrix'

 class Matrix
     def to_pretty_s
         s = ""
         i = 0
         while i < self.column_size
             s += "\n" if i != 0
             j = 0
             while j < self.row_size
                 s += ' ' if j != 0
                 s += self.element(i, j).to_s
                 j += 1
             end
             i += 1
         end
         s
     end

     def to_readable
         maximal_length = 15
         column_counter = 0
         columns_arrays = []
         while column_counter < self.column_size
             maximum_length = 0
             self.column(column_counter).each do |column_element|# Get maximal size
                 length = column_element.to_s.size
                 if length > maximal_length
                     maximum_length = length
                 end
             end # now we've got the maximum size
             column_array = []
             self.column(column_counter).each do |column_element| # Add needed spaces to equalize each column
                 element_string = column_element.to_s
                 element_size = element_string.size
                 space_needed = maximal_length - element_size +1
                 if space_needed > 0
                     space_needed.times {element_string.prepend " "}
                     if column_counter == 0
                         element_string.prepend "["
                     else
                         element_string.prepend ","
                     end
                 end
                 column_array << element_string
             end
             columns_arrays << column_array # Now columns contains equal size strings
             column_counter += 1
         end
         row_counter = 0
         while row_counter < self.row_size
             columns_arrays.each do |column|
                 element = column[row_counter]
                 print element #Each column yield the correspondant row in order
             end
             print "]\n"
             row_counter += 1
         end
     end

     def my_print
         matrix = self.to_a
         field_size = matrix.flatten.collect{|i|i.to_s.size}.max
         matrix.each do |row|
             puts (row.collect{|i| ' ' * (field_size - i.to_s.size) + i.to_s}).join('  ')
         end
     end
 end

 m = Matrix[[12345678910, 333, 22.111], [3, 0.12345678, 3], [-333, 3, 4]]

 puts m # same as puts m.to_s
 puts m.to_pretty_s
 p m.to_pretty_s
 m.to_readable
 m.my_print
 # Matrix[[12345678910, 333, 22.111], [3, 0.12345678, 3], [-333, 3, 4]]
 # 12345678910 333 22.111
 # 3 0.12345678 3
 # -333 3 4
 # "12345678910 333 22.111\n3 0.12345678 3\n-333 3 4"
 # [     12345678910,             333,          22.111]
 # [               3,      0.12345678,               3]
 # [            -333,               3,               4]
 # 12345678910          333       22.111
 #           3   0.12345678            3
 #        -333            3            4