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 _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
