added notes on INF

[rrdtool.git] / doc / rrdgraph_data.src

diff --git a/doc/rrdgraph_data.src b/doc/rrdgraph_data.src
index 47a7bea..f5c1114 100644 (file)
--- a/doc/rrdgraph_data.src
+++ b/doc/rrdgraph_data.src
@@ -1,8 +1,8 @@
 =include name
 
-=head1 SYNOPSYS
+=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>>]
+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>
 
@@ -13,19 +13,19 @@ 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<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>>]
+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>.
+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!
@@ -39,6 +39,11 @@ 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
@@ -56,8 +61,7 @@ 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>