require "rubygems"
require "facets"
require "narray"

module NMatrixExtensions
  def pretty_string(opts={})
    { :col_header   => nil,
      :row_header   => nil }.merge!(opts)

    ("%-3s" % "#") + opts[:col_header].inject("") { |s, a|
      s + ("%7s" % a)
    } + "\n" + self.to_a.map_with_index { |a, i|
      ("%-3s" % opts[:row_header][i]) + a.inject("") { |s, v|
        if v.is_a? Float
          s + ("%7.2f" % v)
        else
          s + ("%7d" % v)
        end
      }
    }.join("\n")
  end
end

NMatrix.send(:include, NMatrixExtensions)