X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=doc%2Frrdgraph_data.src;h=bef369017200db68041c06bd00c0c3581e5a0237;hb=09fa22ce43438f77625e759d7b29d8ae6bc56084;hp=9b9ec8adda42550e93964cc27c874df58925ca19;hpb=0f74f3aef704e1bed50eb540cb1f19097473639b;p=rrdtool.git

diff --git a/doc/rrdgraph_data.src b/doc/rrdgraph_data.src
index 9b9ec8a..bef3690 100644
--- a/doc/rrdgraph_data.src
+++ b/doc/rrdgraph_data.src
@@ -1,8 +1,10 @@
-=include name
+=head1 NAME
 
-=head1 SYNOPSYS
+rrdgraph_data - preparing data for graphing in rrdtool graph
 
-B<DEF>:I<vname>=I<RRD file>:I<ds name>:I<CF>[:step=I<step size>][:<time range>>]
+=head1 SYNOPSIS
+
+B<DEF:>I<E<lt>vnameE<gt>>=I<E<lt>rrdfileE<gt>>:I<E<lt>ds-nameE<gt>>:I<E<lt>CFE<gt>>[:step=I<E<lt>stepE<gt>>][:start=I<E<lt>timeE<gt>>][:end=I<E<lt>timeE<gt>>][:reduce=I<E<lt>B<CF>E<gt>>]
 
 B<VDEF>:I<vname>=I<RPN expression>
 
@@ -13,22 +15,22 @@ B<CDEF>:I<vname>=I<RPN expression>
 These three instructions collect the data out of the B<RRD> files,
 optionally altering it (think of a bytes to bits conversion) and
 if desired you can define variables containing useful information
-such as maximum, mininimum etcetera. Two of the instructions use
+such as maximum, minimum etcetera. Two of the instructions use
 a language called B<RPN> which is described in its own manual page.
 
 =head1 DEF
 
-B<DEF>:I<vname>=I<RRD file>:I<ds name>:I<CF>[:step=I<step size>][:<time range>>]
+B<DEF:>I<E<lt>vnameE<gt>>=I<E<lt>rrdfileE<gt>>:I<E<lt>ds-nameE<gt>>:I<E<lt>CFE<gt>>[:step=I<E<lt>stepE<gt>>][:start=I<E<lt>timeE<gt>>][:end=I<E<lt>timeE<gt>>][:reduce=I<E<lt>B<CF>E<gt>>]
 
 This command fetches data from an B<RRD> file.  The virtual name
 I<vname> can then be used throughout the rest of the script. By
 default, an B<RRA> which contains the correct consolidated data
 at an appropriate resolution will be chosen.  The resolution can
-be overriden with the L<--step|rrdgraph/item_Time> option. 
-The resolution can again be overriden by specifying the B<step size>.
-I<Not yet implemented:> [ The time span of this data
-is the same as for the graph by default, you can override this by
-specifying the B<time range>. ]
+be overridden with the L<--step|rrdgraph/item_Time> option. 
+The resolution can again be overridden by specifying the B<step size>.
+The time span of this data is the same as for the graph by default,
+you can override this by specifying B<start and end>.  Remember to
+escape colons in the time specification!
 
 If the resolution of the data is higher than the resolution of off
 graph, the data will be further consolidated.  This may result in
@@ -39,10 +41,17 @@ a resolution of 1800 seconds per B<CDP>, you should create an
 image with width 400 and time span 400*1800 seconds (use appropriate
 start and end times, such as C<--start end-8days8hours>).
 
+If consolidation needs to be done, the B<CF> of the B<RRA> specified in the
+B<DEF> itself will be used to reduce the data density.  This behaviour can
+be changed using C<:reduce=I<E<lt>B<CF>E<gt>>>.  This optional parameter
+specifies the B<CF> to use during the data reduction phase.
+
 Example:
 
         DEF:ds0=router.rrd:ds0:AVERAGE
         DEF:ds0weekly=router.rrd:ds0:AVERAGE:step=7200
+        DEF:ds0weekly=router.rrd:ds0:AVERAGE:start=end-1h
+        DEF:ds0weekly=router.rrd:ds0:AVERAGE:start=11\:00:end=start+1h
 
 =head1 VDEF
 
@@ -54,8 +63,7 @@ functions used, have a value and a time component.  When you use
 this I<vname> in another B<RPN> expression, you are effectively
 inserting its value just as if you had put a number at that place.
 The variable can also be used in the various graph and print
-elements. I<Not yet implemented:> [ Everywhere you can insert a
-number, you can also use the B<VDEF> (provided that it is set of course) ]
+elements.
 
 Example: C<VDEF:avg=mydata,AVERAGE>
 
@@ -71,4 +79,17 @@ the script, just as if it were generated by a B<DEF> instruction.
 
 Example: C<CDEF:mydatabits=mydata,8,*>
 
-=include see_also
+=head1 SEE ALSO
+
+L<rrdgraph> gives an overview of how B<rrdtool graph> works.
+L<rrdgraph_data> describes B<DEF>,B<CDEF> and B<VDEF> in detail,
+L<rrdgraph_rpn> describes the B<RPN> language used in the B<?DEF> statements,
+L<rrdgraph_graph> page describes all of the graph and print functions.
+
+Make sure to read L<rrdgraph_examples> for tipsE<amp>tricks.
+
+=head1 AUTHOR
+
+Program by Tobias Oetiker E<lt>oetiker@ee.ethz.chE<gt>
+
+This manual page by Alex van den Bogaerdt E<lt>alex@ergens.op.het.netE<gt>