Circle in matrix

gistfile1.txt

require 'matrix'

# Matrix enhance
class Matrix
  def []=(i, j, x)
    @rows[i][j] = x
  end
end

#
center = 6
radius = 5
width = (radius+2)*2
matrix = Matrix.build(width,width){|y,x| [0,0]}
vector = []
output = ""
width.times do |y|
  width.times do |x|
    nx = x-center
    ny = y-center
    distance = Math.hypot(nx, ny)
    puts "#{x}:#{y} = #{distance}"
    if distance <= radius
      matrix[x,y] = [nx,ny]
      vector << [nx,ny]
      output +="1"
    else
      output += "0"
    end
  end
  output += "\n"
end

puts "\n\n" + output