[rrd-users] the usage of CF

[Alex van den Bogaerdt]

----- Original Message ----- 
From: "dophine" <dophinehk at hotmail.com>
To: <rrd-users at lists.oetiker.ch>
Sent: Wednesday, September 23, 2009 6:02 PM
Subject: [rrd-users] the usage of CF


>
> Hi all,
>
> I have question using CF MAX and LAST. I have 80000 data point for each
> second.
> And I plot a chart with the step size 1. However, I found the chart using
> MAX CF and LAST are different.
>
> Does anyone know the reason?


Step size 1 means 1 second.  You claim to have 80,000 datapoints per second, 
I'm only going to show 5 per second. This is what happens when 5 datapoints 
are consolidated into one:

LAST(10,20,30,20,10)==10
MAX(10,20,30,20,10)==30