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<div class="moz-cite-prefix">Hello,
<blockquote cite="mid:71498F2E509345E8B682A135CFA0F6F1@DESK"
type="cite">
<blockquote type="cite">
<pre wrap="">
So, a VDEF is a set of data and a CDEF is a single value, but a TOTAL
will be a single value?
</pre>
</blockquote>
</blockquote>
no, it is opposite :<br>
<a class="moz-txt-link-freetext" href="http://oss.oetiker.ch/rrdtool/doc/rrdgraph_data.en.html#IVDEF">http://oss.oetiker.ch/rrdtool/doc/rrdgraph_data.en.html#IVDEF</a><br>
<a class="moz-txt-link-freetext" href="http://oss.oetiker.ch/rrdtool/doc/rrdgraph_data.en.html#ICDEF">http://oss.oetiker.ch/rrdtool/doc/rrdgraph_data.en.html#ICDEF</a><br>
<br>
CDEF and DEF, are series of values, number of value depends on
step parameter an the consolidation function (<i>CF</i>).<br>
VDEF is a single value.<br>
<br>
You cant use CDEF without DEF or CDEF variables because you can't
calculate number of value needed for series.<br>
<br>
Le 21/02/2013 22:37, Alex van den Bogaerdt a écrit :<br>
</div>
<blockquote cite="mid:71498F2E509345E8B682A135CFA0F6F1@DESK"
type="cite">
<blockquote type="cite">
<pre wrap="">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?
</pre>
</blockquote>
<pre wrap="">
VDEF support is currently very limited. What you are trying to do is,
indeed, not possible this way.
</pre>
<blockquote type="cite">
<pre wrap="">I am trying to take two totals and add them together - seems fairly
common to want to do this?
</pre>
</blockquote>
<pre wrap="">
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
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</pre>
</blockquote>
<br>
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