[rrd-users] clarification of graph resolution
linux at thehobsons.co.uk
Tue May 8 20:30:05 CEST 2007
Spencer Anderson wrote:
>I am trying to pick the best graph size for the data I'm trying to
>present. I collect data every minute and would like to show 24
>hours of data on one graph. Am I correct in assuming that at the
>default resolution, 1 data point = 1 pixel, I would need a graph
>1440 (24 hours * 60 minutes) pixels wide to hold all the data points?
>Also, if I leave the default resolution, and create a "last 24
>hours" graph that is 600 pixels wide, the data still looks like it
>is my one minute data points, even thought there is no way they
>could all fit in a 600 pixel graph. Is RRD averaging the data
>points so they fit, or just skipping some so they fit?
It fits the data to the graph - so if for example you have 2 1/2 data
points/pixel, the first pixel would be (a+b+c/2)/2.5, the next would
be (c/2+d+e)/2.5, and so on.
More information about the rrd-users