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Re: runtime status
- From: Jim Keniston <jkenisto at us dot ibm dot com>
- To: Martin Hunt <hunt at redhat dot com>
- Cc: SystemTAP <systemtap at sources dot redhat dot com>
- Date: 02 Jun 2005 15:12:05 -0700
- Subject: Re: runtime status
- Organization:
- References: <1117696984.1063.25.camel@tiger>
On Thu, 2005-06-02 at 00:23, Martin Hunt wrote:
...
> --- STATS ---
> %m - min
> %M - max
> %A - avg
> %S - sum
> %H - histogram
> %C - count
Consider also computing variance, which can be computed from the sum and
count (which you're already computing) and the sum of x*x (x*x = the
square of the observed value):
variance = SS/(n - 1)
SS = sum of x*x - ((sum*sum)/n)
Of course, you'd lose some precision due to integer arithmetic.
Standard deviation (sqrt(variance)) would be even nicer, but I don't
think sqrt() is something you want to add to the kernel.:-)
Jim