[rrd-users] Is there a setting to smoothen a graph?

[Marc MERLIN]

Let's take this
http://graphs.merlins.org/graphs/g.php?action=zoom&local_graph_id=70&rra_id=6&view_type=&graph_start=1279409518&graph_end=1279409978&graph_height=240&graph_width=800&title_font_size=12

as a zoom of
http://graphs.merlins.org/graphs/g.php?action=zoom&local_graph_id=70&rra_id=6&view_type=&graph_start=1279380998&graph_end=1279438498&graph_height=240&graph_width=800&title_font_size=12

My problem is that I'd like 10 seconds updates to catch transient
electricity changes, but at a 10 second update rate, during 10 seconds, my
counter can oscilate between 5 and 6Wh per time slice, causing the ugly
stair effect.

I have cacti configured to generate the graph with this command:
/usr/bin/rrdtool graph - \
--imgformat=PNG \
--start=-86400 \
--end=-50 \
--title="ECM House PV" \
--base=1000 \
--height=240 \
--width=800 \
--alt-autoscale \
--vertical-label="Wh" \
--slope-mode \
--font TITLE:12: \
--font AXIS:8: \
--font LEGEND:10: \
--font UNIT:8: \
DEF:a="/var/lib/cacti/rra/houseecm1_25.rrd":PV:AVERAGE \
CDEF:cdefa=a,3600,* \
AREA:cdefa#0000FFFF:"Power"  \
GPRINT:cdefa:LAST:"             Current\:%8.0lf Wh"  \
GPRINT:cdefa:AVERAGE:"Average\:%8.0lf Wh"  \
GPRINT:cdefa:MIN:"Minimum%8.0lf Wh"  \
GPRINT:cdefa:MAX:"Maximum\:%8.0lf Wh\n" 

Are there other settings I can use, or am I out of luck if I don't have
higher solution counters?

Thanks,
Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems & security ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/