<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Perfect, just what I needed. <div><br></div><div>I <i>knew</i> this slick software would be up to the task...</div><div><br></div><div>Jeff<br><div><div>On Jul 7, 2011, at 9:13 PM, Alex van den Bogaerdt wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><blockquote type="cite">Hi folks,<br></blockquote><blockquote type="cite"><span class="Apple-tab-span" style="white-space:pre"> </span>I am new to RRD and still trying to wrap my mind around the power of this<br></blockquote><blockquote type="cite">excellent tool. I am working on an application to use RRD to store<br></blockquote><blockquote type="cite">electricity meter data for a group of homes. I am expecting to create an<br></blockquote><blockquote type="cite">RRD file for each home, and it will have a number of RRA's defined for<br></blockquote><blockquote type="cite">various time periods.<br></blockquote><br>Good. I suggest you store Joules, or kilowatthours.<br><br><blockquote type="cite">In addition to displaying the individual house data graphs, I would like<br></blockquote><blockquote type="cite">to also create graphs that show aggregated results drawn from the house<br></blockquote><blockquote type="cite">RRD files. For example, I might show the combined power draw in watts for<br></blockquote><blockquote type="cite">the 8 homes that make up a quadrant of my neighborhood, or show the total<br></blockquote><blockquote type="cite">power draw from all 30 homes.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Is there a reasonably-straightforward way to do this in RRD?<br></blockquote><br>DEF:meter1=/home/user/data/rrd/house1.rrd:meter:AVERAGE<br>DEF:meter2=/home/user/data/rrd/house2.rrd:meter:AVERAGE<br>DEF:meter3=/home/user/data/rrd/house3.rrd:meter:AVERAGE<br>[...]<br>CDEF:total=meter1,meter2,meter3....<br>[...]<br>LINE1:total#000:total<br><br><br>There are several things to improve in this (incomplete) example, but what<br>I show here is the answer to your question: how to combine data from<br>several sources.<br><br>Another example (using the same DEFs):<br><br>[...]<br>AREA:meter1#F00<br>AREA:meter2#FC0::STACK<br>AREA:meter3#0C0::STACK<br>AREA:meter4#F00::STACK<br>[...]<br><br>_______________________________________________<br>rrd-users mailing list<br><a href="mailto:rrd-users@lists.oetiker.ch">rrd-users@lists.oetiker.ch</a><br>https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users<br></div></blockquote></div><br></div></body></html>