gistfile1.rb

require 'narray'

# cheap & easy way to do this...
matrix = []
File.open("numbers.file") do |file|
  file.each_line do |line|
    ary = []
    line.split(" ").each{ |n| ary << n.to_f }
    matrix << ary
  end
end
matrix = NArray.to_na(matrix)

numbers.file

1 2
3 4

output

[[1.0, 2.0], [3.0, 4.0]]