Thank you for letting me know how VDEF works. ----- Original Message ----- From: "Yannick Marquet" <itcsof...@yahoo.fr> To: "Alex van den Bogaerdt" <a...@vandenbogaerdt.nl> Cc: <rrd-users@lists.oetiker.ch> Sent: Saturday, February 23, 2013 2:12 PM Subject: Re: [rrd-users] Adding two VDEF values together
> Hello, >>> So, a VDEF is a set of data and a CDEF is a single value, but a TOTAL >>> will be a single value? > no, it is opposite : > http://oss.oetiker.ch/rrdtool/doc/rrdgraph_data.en.html#IVDEF > http://oss.oetiker.ch/rrdtool/doc/rrdgraph_data.en.html#ICDEF > > CDEF and DEF, are series of values, number of value depends on step > parameter an the consolidation function (/CF/). > VDEF is a single value. > > You cant use CDEF without DEF or CDEF variables because you can't > calculate number of value needed for series. > > Le 21/02/2013 22:37, Alex van den Bogaerdt a écrit : >>> I was trying to do something which I thought was fairly simple, but I >>> keep on getting the following error: >>> >>> "ERROR: rpn expressions without DEF or CDEF variables are not supported" >>> >>> In the most simplest form, I am trying to do the following: >>> >>> DEF:A=<rrdfile>:A:AVERAGE >>> DEF:B=<rrdfile>:B:AVERAGE >>> >>> VDEF:TA=A,TOTAL >>> VDEF:TB=B,TOTAL >>> >>> CDEF:TAB=TA,TB,ADDNAN >>> >>> So, a VDEF is a set of data and a CDEF is a single value, but a TOTAL >>> will be a single value? >> VDEF support is currently very limited. What you are trying to do is, >> indeed, not possible this way. >> >>> I am trying to take two totals and add them together - seems fairly >>> common to want to do this? >> The workaround is to do your math inside a CDEF, and then find the total. >> >> CDEF:c=a,b,ADDNAN >> VDEF:total=c,TOTAL >> >> hth >> alex >> >> _______________________________________________ >> rrd-users mailing list >> rrd-users@lists.oetiker.ch >> https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users >> > > _______________________________________________ rrd-users mailing list rrd-users@lists.oetiker.ch https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
