You can use the CloudWatch console to graph metric data generated by AWS services and your applications. Now, you can zoom into a shorter time period such as one minute or five minutes while viewing the metric graph at a longer interval.
Pan 則是維持一樣的粒度，但改變開始與結束的時間：
Once zoomed, you can also pan the metric graph across your selected interval, but at a zoomed detail level.
Score = Lower bound of Wilson score confidence interval for a Bernoulli parameter
但實際的運算其實沒那麼複雜，像是 Ruby 的程式碼可以看出大多都是系統內的運算就可以算出來。其中的 z 在大多數的情況下是常數。
require 'statistics2'
def ci_lower_bound(pos, n, confidence)
if n == 0
return 0
end
z = Statistics2.pnormaldist(1-(1-confidence)/2)
phat = 1.0*pos/n
(phat + z*z/(2*n) - z * Math.sqrt((phat*(1-phat)+z*z/(4*n))/n))/(1+z*z/n)
end
The z-score in this function never changes, so if you don't have a statistics package handy or if performance is an issue you can always hard-code a value here for z. (Use 1.96 for a confidence level of 0.95.)
