=head1 NAME

rrdtool graph - Round Robin Database tool grapher functions

WARNING: This is for version 1.1.x which is B<I<BETA>> software.
The software may contain serious bugs. Some of the items
described in here may not yet exist (although this should
be mentioned) or still be in the alpha stage.  As with every
other RRDtool release: use at your own risk.  In contrast with
the stable version of RRDtool, this release may contain bugs
known to the authors.  It is highly recommended that you subscribe
to the mailing list.

=head1 SYNOPSYS

I<(to be) Depriciated commands>

[B<PRINT:>I<vname>B<:>I<CF>B<:>I<format>]
[B<GPRINT:>I<vname>B<:>I<CF>B<:>I<format>]
[B<HRULE:>I<value>B<#>I<rrggbb>[B<:>I<legend>]]
[B<STACK:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]]]

I<(soon) available commands>

[B<PRINT:>I<vname>B<:>I<format>]
[B<GPRINT:>I<vname>B<:>I<format>]
[B<COMMENT:>I<text>]
[B<VRULE:>I<vname>B<#>I<rrggbb>[B<:>I<legend>]]
[B<LINE>{B<1>|B<2>|B<3>}B<:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]]][B<:STACK>]
[B<AREA:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]]][B<:STACK>]

I<to be implemented commands>

[B<SHIFT:>I<vname>]
[B<PART:>I<vname>B<#>I<rrggbb>[B<:>I<legend>]]

=head1 DESCRIPTION

These instructions allow you to generate your image or report.
If you don't use any graph elements, no graph is generated.
Similarly no report is generated if you don't use print options.

=head1 PRINT

B<PRINT:>I<vname>B<:>I<CF>B<:>I<format>

I<Depriciated. Use the new form of this command in new scripts.>
The first form of this command is to be used with B<CDEF> I<vname>s.

B<PRINT:>I<vname>B<:>I<format>

Depending on the context, either the value component or the time
component of a B<VDEF> is printed using I<format>. It is an error
to specify a I<vname> generated by a B<DEF> or B<CDEF>.

Any text in I<format> is printed literally with one exception:
The percent character introduces a formatter string. This string
can be:

For printing values:

=over 4

=item *

B<%%> just prints a literal '%' character

=item *

B<%#.#le> (where # is an optional number) prints like 1.2346e+04

=item *

B<%#.#lf> prints like 12345.6789

=item *

B<%s> place this after B<%le> or B<%lf>.  This will be replaced by the
appropriate SI magnitude unit and the value will be scaled
accordingly (123456 -> 123.456 k)

=item *

B<%S> is similar to B<%s>. It does however use a previously defined
magnitude unit. If there is no such unit yet, it tries to define
one (just like B<%s>). However, if the value is zero, the magnitude
unit stays undefined. Thus, formatter strings using B<%S> and no B<%s>
will all use the same magnitude unit except for zero values.

=back

For printing times:

=over 4

=item *

B<%%> just prints a literal '%' character

=item *

B<%a, %A> prints abbreviated, full weekday name

=item *

B<%b, %B> prints abbreviated, full month name

=item *

B<%d, %m, %y, %H, %M, %S> day,month,year,hour,minute,second all in two-digit format

=item *

B<%Y> year in 4-digit format

=item *

B<%I, %p>  hour (01..12), 'am' or 'pm'

=item *

B<%j, %w> day of the week (0..6), day of the year (1..366)

=item *

B<%c, %x, %X> date+time, date, time

=item *

B<%U, %W> week number of the current year with either the first sunday or
the first monday determining the first week

=item *

B<%Z> time zone

=back

=head1 GRAPH

B<GPRINT:>I<vname>B<:>I<CF>B<:>I<format>

I<Depriciated. Use the new form of this command in new scripts.>
This is the same as B<PRINT> but now it is printed inside the graph.
See L<PRINT> for more information.

B<GPRINT:>I<vname>B<:>I<format>

This is the same as B<PRINT> but now it is printed inside the graph.
See L<PRINT> for more information.

B<COMMENT:>I<text>

Text is printed literally in the legend section of the graph

B<HRULE:>I<value>B<#>I<rrggbb>[B<:>I<legend>]

Draw an horizontal line at I<value>. Its color is composed from three
hexadecimal numbers specifying the color components (00 is off, FF is
maximum) red, green and blue.  Optionally a legend box and string is
printed in the legend section. I<value> can be a variable from a B<VDEF>.
It is an error to use I<vname>s from B<DEF> or B<CDEF> here.

B<VRULE:>I<time>B<#>I<rrggbb>[B<:>I<legend>]

Draw a vertical line at I<time>.  Its color is composed from three
hexadecimal numbers specifying the color components (00 is off, FF is
maximum) red, green and blue.  Optionally a legend box and string is
printed in the legend section. I<time> may be a number or a variable
from a B<VDEF>. It is an error to use I<vname>s from B<DEF> or B<CDEF> here.

B<LINE>{B<1>|B<2>|B<3>}B<:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]][B<:STACK>]

Draw a line of the specified width into the graph. If the color
is not specified, the drawing is done 'blind'.  This is useful when
stacking something else on top of this line. Also optional is the
legend box and string which will be printed in the legend section
if specified. The B<vname> can be generated by B<DEF>, B<VDEF> and
B<CDEF>.  If the optional B<STACK> modifier is used, this line is
stacked on top of the previous element which can be a B<LINEx> or
an B<AREA>

B<AREA:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]][B<:STACK>]

See B<LINEx>, however the area between the x-axis and the line will
also be filled.

B<STACK:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]]

I<Depriciated.  Use the B<STACK> modifiers on the other commands.>
I<Note: the comments on stacking are still valid...>
Repeats the last B<LINEx> or B<AREA> however it doesn't start at the
x-axis but rather on top of the previous element. This implies that
there needs to be something to stack on. An invisible B<LINEx> or
B<AREA> is something you can stack on!

Note: When you stack on something that was I<unknown>, the whole
stack will be I<unknown> for that point in time. If the beginning
is undefined, there's no way to end somewhere...  If you want to
graph this stacked variable anyway you need to make sure that the
B<LINEx> or B<AREA> it gets stacked on is not unknown. Use a CDEF
instruction with B<IF> and B<UN> to do so.

B<THE NEXT STUFF IS NOT YET IMPLEMENTED>

B<SHIFT:>I<offset in seconds>

Using this command B<RRDtool> will graph the following elements
with the specified offset.  For instance, you can specify an
offset of S<( 7*24*60*60 = ) 604800 seconds> to "look back" one
week. Make sure to notify the viewer you did so...
The offset will be valid until the next B<SHIFT> command, which
can have an offset of zero to restore normal graphing.
As with the other grapher elements, you can specify a number or
a variable here.

B<RRDtool> has now support for B<pie charts>. If you include the
B<PART> command, the canvas is extended to make room for a chart
(or, if no other graph elements are used, the canvas is solely
used for the pie chart). The size of the canvas is determined by
the lesser of L<width and height|rrdgraph/item_Size>.

B<PART:>I<vname>B<#>I<rrggbb>[B<:>I<legend>]

Draw a part of pie. Pie parts will be concatenated, the first one
will start at the top and parts will be created clockwise.
The size of the part is defined by the value part of
the L<VDEF|rrdgraph_data/VDEF> function.  It should return
a number between 0 and 100, being a percentage.
Providing wrong input will produce undefined results.

=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>