# [rrd-users] [Fwd: Re: Re: Calculating average when aggregating]

Stephan Harren sh at abovenet.de
Mon Aug 5 15:48:29 MEST 2002

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-------- Original Message --------
Subject: Re: [rrd-users] Re: Calculating average when aggregating
Date: Mon, 05 Aug 2002 15:26:11 +0200
From: Stephan Harren <sh at abovenet.de>
To: Geert van der Ploeg <rrd at geert.triple-it.nl>
References: <3D4E3C47.20602 at abovenet.de>
<00a301c23c5e\$6896c960\$d201a8c0 at peasant> <3D4E4315.2090102 at abovenet.de>
<012101c23c74\$91274ce0\$d201a8c0 at peasant> <3D4E72F5.1030309 at abovenet.de>
<020401c23c81\$9cf19140\$d201a8c0 at peasant>

> What is your way of averaging?
> We should be able to determine what the outcome should be, following the
> calculation.
>
>
> If the average does not start at the beginning and doesn't do the
> calculation right, a (nasty) solution would be to change the UNKNOWN
value
> to the value of the 'known' DS.
> Thus, you get an average which is equal to the only known DS, as long
as the
> other, UNKNOWN DS is unknown.
> That would be something like: ds1,UN,ds0,ds1,IF (where ds1 is the
unkwown,
> newest DS, and ds0 the DS that started 6 months ago)
>
>
WOW, cool! But as you said, nasty. Anyway, this is not very handy if
you've got twelve datasources ...

O.K., my way of averaging would be like:

DS1		DS2	  	 AGGREGATED

Timestamp1:
20		NaN			20
Timestamp2:
10		NaN			10
Timestamp3:
20		10			30

Sum of the three timestamps is 60 so the average should be 20
If the Print-Command behaves like the graphing it will look like this:

DS1		DS2	  	AGGREGATED

Timestamp1:
20		NaN			NaN
Timestamp2:
10		NaN			NaN
Timestamp3:
20		10			30

There is only one valid timestmp, so the average will be 30.

Have you ever tried this ?

Best regards,

Stephan
--
Stephan Harren
Manager Site Operations
MFN-IS Germany
Tel 	0049 69 90554 153
Cell
0049 173 7011126
Fax
0049 69 90554 111

--
Stephan Harren
Manager Site Operations
MFN-IS Germany
Tel 	0049 69 90554 153
Cell
0049 173 7011126
Fax
0049 69 90554 111

--
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