# File lib/mongrel/stats.rb, line 64
64:     def sd
65:       # (sqrt( ((s).sumsq - ( (s).sum * (s).sum / (s).n)) / ((s).n-1) ))
66:       begin
67:         return Math.sqrt( (@sumsq - ( @sum * @sum / @n)) / (@n-1) )
68:       rescue Errno::EDOM
69:         return 0.0
70:       end
71:     end