Hi Steve and Tobi, Thanks so much for the insight and RRD-kungfu. That worked.
Owe you all one. - Rob On Nov 10, 2010, at 6:17 PM, Tobias Oetiker wrote: > Today Steve Shipway wrote: > >> Have you tried this: >> >> CDEF:dtmaxdiff=dt,POP,dtfoo,16,- >> >> This uses a DEF variable (dt) although it is removed by the POP >> to trick the CDEF into having at least one dataset variable (dt) >> to base the new sequence off of. I'm still not sure if RRDTool >> lets you use the VDEF value as a constant, though... I suspect >> not but havent tried it in the latest version of RRDTool > > this will work > tobi > >> >> Steve >> Steve Shipway >> University of Auckland ITS >> UNIX Systems Design Lead >> [email protected]<mailto:[email protected]> >> Ph: +64 9 373 7599 ext 86487 >> >> ________________________________ >> From: [email protected] >> [[email protected]] on behalf of >> Rob Newman [[email protected]] >> Sent: Thursday, 11 November 2010 2:03 p.m. >> To: [email protected] >> Subject: [rrd-users] Concatenated VDEF and CDEF commands in a rrdtool graph >> cmd >> >> Hi there, >> >> Does anyone know why this fails: >> >> rrdtool graph /path/to/outputimage/rrd.png \ >> --interlaced --imgformat PNG --end 1289434618 --start 1286756217 \ >> --width 600 --height 200 --title 'TEST' \ >> DEF:dt=/path/to/dt.rrd:dt:AVERAGE \ >> VDEF:dtfoo=dt,MAXIMUM \ >> CDEF:dtmaxdiff=dtfoo,16,- \ >> LINE1:dtmaxdiff#990000:'TESTFOO' \ >> GPRINT:dt:LAST:'Latest value for TESTFOO\: %4.0lf%s\j' >> >> The output I get from rrdtool is: >> >> ERROR: rpn expressions without DEF or CDEF variables are not supported >> >> If I try and add backslashes to the path (a la >> http://www.mrtg.org/rrdtool/doc/rrdgraph_rpn.en.html, note between the VDEF >> and CDEF rpn command there is not a carriage return anymore, just whitespace >> and a backslash): >> >> rrdtool graph /path/to/outputimage/rrd.png \ >> --interlaced --imgformat PNG --end 1289434618 --start 1286756217 \ >> --width 600 --height 200 --title 'TEST' \ >> DEF:dt=/path/to/dt.rrd:dt:AVERAGE \ >> VDEF:dtfoo=dt,MAXIMUM \ CDEF:dtmaxdiff=dtfoo,16,- \ >> LINE1:dtmaxdiff#990000:'TESTFOO' \ >> GPRINT:dt:LAST:'Latest value for TESTFOO\: %4.0lf%s\j' >> >> I now get the output: >> >> ERROR: Could not make sense out of ' CDEF:dtmaxdiff=dtfoo,16,-' >> >> What I want is to find the maximum value for the data set ('dtfoo = >> dt,MAXIMUM'), then take that value and subtract 16 from it (dtmaxdiff = >> dtfoo,16,-), then plot that value. >> >> Any ideas why both of these fail? >> >> Thanks in advance, >> - Rob >> > > -- > Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland > http://it.oetiker.ch [email protected] ++41 62 775 9902 / sb: -9900 ________________________________________________________ Rob Newman Ph.D. Institute of Geophysics and Planetary Physics Scripps Institution of Oceanography University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093-0225, USA _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
