[rrd-users] [GRAYMAIL] Doubt work rrdtool intervals

[rseiwert]

I believe that RRDtool starts at zero no matter what you say the start is but I might be wrong on that and then calculates buckets based on the step. If your update is not exactly on the step boundry (starting from zero) then your updates will be interpolated.  Your updates are between these steps so they are being interpolated.  Use dump to look at your raw data.

From: spiderslack [via RRD Mailinglists] [mailto:ml-node+s937164n7582142h53 at n2.nabble.com]
Sent: Wednesday, June 04, 2014 6:56 PM
To: Robert C. Seiwert
Subject: [GRAYMAIL] Doubt work rrdtool intervals

Hi all.

I've been studying the rrdtool tutorial I found very interesting and
fantastic.
http://oss.oetiker.ch/rrdtool/tut/rrdtutorial.en.html
But when trying to play the tutorial with example of my data got the
following output.


+ rrdtool create kakaroto.rrd --start N --step 15
DS:dados:COUNTER:20:U:U RRA:AVERAGE:0.5:1:60 RRA:AVERAGE:0.5:6:5
++ date +%s
+ ATUAL=1401916330
+ sleep 15
++ date +%s
+ rrdtool update kakaroto.rrd 1401916345:2
+ sleep 15
++ date +%s
+ rrdtool update kakaroto.rrd 1401916360:3
+ sleep 15
++ date +%s
+ rrdtool update kakaroto.rrd 1401916375:5
+ sleep 15
++ date +%s
+ rrdtool update kakaroto.rrd 1401916390:7
+ sleep 15
++ date +%s
+ rrdtool update kakaroto.rrd 1401916405:10
+ sleep 15
++ date +%s
+ rrdtool update kakaroto.rrd 1401916420:12
+ sleep 15
++ date +%s
+ rrdtool update kakaroto.rrd 1401916435:15
+ sleep 15
++ date +%s
+ rrdtool update kakaroto.rrd 1401916450:17
+ sleep 15
+ rrdtool fetch kakaroto.rrd AVERAGE --start 1401916330
dados

1401916335: -nan
1401916350: -nan
1401916365: 8.8888888889e-02
1401916380: 1.3333333333e-01
1401916395: 1.5555555556e-01
1401916410: 1.7777777778e-01
1401916425: 1.5555555556e-01
1401916440: 1.7777777778e-01
1401916455: -nan
1401916470: -nan



See that the values ​​are not entered in the exact period
example in period 1401916345 is this between 1401916335 and 1401916350.
but I considered it as if it were entered in the period 1401916350 so my
reasoning is incorrect readjusting my data would thus


1401916335: -nan
1401916350: 2
1401916365: 3
1401916380: 5
1401916395: 7
1401916410: 10
1401916425: 12
1401916440: 15
1401916455: 17
1401916470: -nan


Doing the calculations according to the example of the tutorial
http://oss.oetiker.ch/rrdtool/tut/rrdtutorial.en.html

Using octave


octave:32> abs(2-3)/15
ans = 6.66666666666667E-02
octave:33> abs(3-5)/15
ans = 1.33333333333333E-01
octave:34> abs(5-7)/15
ans = 1.33333333333333E-01
octave:35> abs(7-10)/15
ans = 2.00000000000000E-01
octave:36> abs(10-12)/15
ans = 1.33333333333333E-01
octave:37> abs(12-15)/15
ans = 2.00000000000000E-01
octave:38> abs(15-17)/15
ans = 1.33333333333333E-01
octave:39>


See that the values ​​are different where I am going wrong? thank you

Regards

_______________________________________________
rrd-users mailing list
[hidden email]</user/SendEmail.jtp?type=node&node=7582142&i=0>
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

________________________________
If you reply to this email, your message will be added to the discussion below:
http://rrd-mailinglists.937164.n2.nabble.com/Doubt-work-rrdtool-intervals-tp7582142.html
To start a new topic under RRDtool Users Mailinglist, email ml-node+s937164n937053h94 at n2.nabble.com<mailto:ml-node+s937164n937053h94 at n2.nabble.com>
To unsubscribe from RRD Mailinglists, click here<http://rrd-mailinglists.937164.n2.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=937164&code=cm9iQHZjYS5jb218OTM3MTY0fC0xMzA5NDI1MzI4>.
NAML<http://rrd-mailinglists.937164.n2.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml>




--
View this message in context: http://rrd-mailinglists.937164.n2.nabble.com/Doubt-work-rrdtool-intervals-tp7582142p7582143.html
Sent from the RRDtool Users Mailinglist mailing list archive at Nabble.com.