a_(i,i)=1,a_(i,i-1)=1,a_(i,i+1)=1な行列を生成するスクリプト

matrix.rb

require 'matrix'

# 情報数学概論の検証
def matrix(row_size,col_size = row_size)
  Matrix.build(row_size, col_size) do | row,col |
    if (row == col) || row == col +1 || row + 1 == col
      1
    else
      0
    end
  end
end

1.upto 50 do |i|
  puts "n=#{i}: #{matrix(i).det}"
end