NAME 
rrdgraph - Round Robin Database tool grapher functions
SYNOPSIS 
rrdtool graph filename[
././rrdgraph.html#optionsoption  ...]
[
././rrdgraph_data.html#defdata definition  ...]
[
././rrdgraph_data.html#cdefdata calculation  ...]
[
././rrdgraph_data.html#vdefvariable definition  ...]
[
././rrdgraph_graph.html#graphgraph element  ...]
[
././rrdgraph_graph.html#printprint element  ...]
DESCRIPTION 
The graph function of RRDtool is used to present the
data from an 
RRD to a human viewer.  Its main purpose is to
create a nice graphical representation, but it can also generate
a numerical report.
OVERVIEW 
rrdtool graph needs data to work with, so you must use one or more
././rrdgraph_data.html#defdata definition  statements to collect this
data.  You are not limited to one database, it's perfectly legal to
collect data from two or more databases (one per statement, though).
If you want to display averages, maxima, percentiles, etcetera
it is best to collect them now using the
././rrdgraph_data.html#vdefvariable definition  statement.
Currently this makes no difference, but in a future version
of rrdtool you may want to collect these values before consolidation.
The data fetched from the RRA is then consolidated so that
there is exactly one datapoint per pixel in the graph. If you do
not take care yourself, 
RRDtool will expand the range slightly
if necessary. Note, in that case the first and/or last pixel may very
well become unknown!
Sometimes data is not exactly in the format you would like to display
it. For instance, you might be collecting 
bytes per second, but
want to display 
bits per second. This is what the ././rrdgraph_data.html#cdefdata calculation  command is designed for. After
consolidating the data, a copy is made and this copy is modified
using a rather powerful 
././rrdgraph_rpn.htmlRPN  command set.
When you are done fetching and processing the data, it is time to
graph it (or print it).  This ends the 
rrdtool graph sequence.
OPTIONS 
filename The name and path of the graph to generate. It is recommended to
end this in 
.png, .svg or .eps, but RRDtool does not enforce this.
filename can be '-' to send the image to stdout. In
this case, no other output is generated.
Time range [
-s|--start time]
[
-e|--end time]
[
-S|--step seconds]
The start and end of the time series you would like to display, and which
RRA the data should come from.  Defaults are: 1 day ago until
now, with the best possible resolution. 
Start and end can
be specified in several formats, see
././rrdfetch.htmlAT-STYLE TIME SPECIFICATION  and ././rrdgraph_examples.htmlthe rrdgraph_examples manpage .
By default, 
rrdtool graph calculates the width of one pixel in
the time domain and tries to get data from an 
RRA with that
resolution.  With the 
step option you can alter this behaviour.
If you want 
rrdtool graph to get data at a one-hour resolution
from the 
RRD, set step to 3'600. Note: a step smaller than
one pixel will silently be ignored.
Labels [
-t|--title string]
[
-v|--vertical-label string]
A horizontal string at the top of the graph and/or a vertically
placed string at the left hand side of the graph.
Size [
-w|--width pixels]
[
-h|--height pixels]
[
-j|--only-graph]
The width and height of the canvas (the part of the graph with
the actual data and such). This defaults to 400 pixels by 100 pixels.
If you specify the --only-graph option and set the height < 32
pixels you will get a tiny graph image (thumbnail) to use as an icon
for use in an overview, for example. All labeling will be stripped off
the graph.
Limits [
-u|--upper-limit value]
[
-l|--lower-limit value]
[
-r|--rigid]
By default the graph will be autoscaling so that it will adjust the
y-axis to the range of the data. You can change this behaviour by
explicitly setting the limits. The displayed y-axis will then range at
least from 
lower-limit to upper-limit. Autoscaling will still
permit those boundaries to be stretched unless the 
rigid option is
set.
[-A|--alt-autoscale]
Sometimes the default algorithm for selecting the y-axis scale is not
satisfactory. Normally the scale is selected from a predefined
set of ranges and this fails miserably when you need to graph something
like 
260 + 0.001 * sin(x). This option calculates the minimum and
maximum y-axis from the actual minimum and maximum data values. Our example
would display slightly less than 
260-0.001 to slightly more than
260+0.001 (this feature was contributed by Sasha Mikheev).
[-M|--alt-autoscale-max]
Where --alt-autoscale will modify both the absolute maximum AND minimum
values, this option will only affect the maximum value. The minimum
value, if not defined on the command line, will be 0. This option can
be useful when graphing router traffic when the WAN line uses compression,
and thus the throughput may be higher than the WAN line speed.
[-N|--no-gridfit]
In order to avoid anti-aliasing effects gridlines are placed on
integer pixel values. This is by default done by extending
the scale so that gridlines happens to be spaced using an
integer number of pixels and also start on an integer pixel value.
This might extend the scale too much for some logarithmic scales
and for linear scales where 
--alt-autoscale is needed.
Using 
--no-gridfit disables modification of the scale.
Grid X-Axis [
-x|--x-grid GTM:GST:MTM:MST:LTM:LST:LPR:LFM]
[-x|--x-grid none]
The x-axis label is quite complex to configure. If you don't have
very special needs it is probably best to rely on the autoconfiguration
to get this right. You can specify the string 
none to suppress the grid
and labels altogether.
The grid is defined by specifying a certain amount of time in the ?TMpositions. You can choose from 
SECOND, MINUTE, HOUR, DAY,
WEEK, MONTH or YEAR. Then you define how many of these should
pass between each line or label.  This pair (
?TM:?ST) needs to be
specified for the base grid (
G??), the major grid (M??) and the
labels (
L??). For the labels you also must define a precision
in 
LPR and a strftime format string in LFM.  LPR defines
where each label will be placed. If it is zero, the label will be
placed right under the corresponding line (useful for hours, dates
etcetera).  If you specify a number of seconds here the label is
centered on this interval (useful for Monday, January etcetera).
 --x-grid MINUTE:10:HOUR:1:HOUR:4:0:%X
This places grid lines every 10 minutes, major grid lines every hour,
and labels every 4 hours. The labels are placed under the major grid
lines as they specify exactly that time.
 --x-grid HOUR:8:DAY:1:DAY:1:0:%A
This places grid lines every 8 hours, major grid lines and labels
each day. The labels are placed exactly between two major grid lines
as they specify the complete day and not just midnight.
Y-Axis [
-y|--y-grid grid step:label factor]
[-y|--y-grid none]
Y-axis grid lines appear at each grid step interval.  Labels are
placed every 
label factor lines.  You can specify -y none to
suppress the grid and labels altogether.  The default for this option is
to automatically select sensible values.
[-Y|--alt-y-grid]
Place the Y grid dynamically based on the graph's Y range. The algorithm
ensures that you always have a grid, that there are enough but not too many
grid lines, and that the grid is metric. That is the grid lines are placed
every 1, 2, 5 or 10 units. This parameter will also ensure that you get
enough decimals displayed even if your graph goes from 69.998 to 70.001. 
(contributed by Sasha Mikheev).
[-o|--logarithmic]
Logarithmic y-axis scaling.
[-X|--units-exponent value]
This sets the 10**exponent scaling of the y-axis values. Normally,
values will be scaled to the appropriate units (k, M, etc.).  However,
you may wish to display units always in k (Kilo, 10e3) even if the data
is in the M (Mega, 10e6) range, for instance. Value should be an
integer which is a multiple of 3 between -18 and 18 inclusively.  It is
the exponent on the units you wish to use. For example, use 3 to
display the y-axis values in k (Kilo, 10e3, thousands), use -6 to
display the y-axis values in u (Micro, 10e-6, millionths).  Use a value
of 0 to prevent any scaling of the y-axis values.
This option is very effective at confusing the heck out of the default
rrdtool autoscaler and grid painter. If rrdtool detects that it is not
successful in labeling the graph under the given circumstances, it will switch
to the more robust 
--alt-y-grid mode.
[-L|--units-length value]
How many digits should rrdtool assume the y-axis labels to be? You
may have to use this option to make enough space once you start
fideling with the y-axis labeling.
Miscellaneous [
-z|--lazy]
Only generate the graph if the current graph is out of date or not
existent.
[-f|--imginfo printfstr]
After the image has been created, the graph function uses printf
together with this format string to create output similar to the PRINT
function, only that the printf function is supplied with the parameters
filename, xsize and ysize. In order to generate an IMG tag
suitable for including the graph into a web page, the command line
would look like this:
 --imginfo '<IMG SRC="/img/%s" WIDTH="%lu" HEIGHT="%lu" ALT="Demo">'
[-c|--color COLORTAG#rrggbb[aa]]
Override the default colors for the standard elements of the graph. The
COLORTAG is one of BACK background, CANVAS for the background of
the actual graph, 
SHADEA for the left and top border, SHADEB for the
right and bottom border, 
GRID, MGRID for the major grid, FONT for
the color of the font, 
AXIS for the axis of the graph, FRAME for the
line around the color spots and finally 
ARROW for the arrow head pointing
up and forward. Each color is composed out of three hexadecimal numbers
specifying its rgb color component (00 is off, FF is maximum) of red, green
and blue. Optionally you may add another hexadecimal number specifying the
transparency (FF is solid). You may set this option several times to alter
multiple defaults.
A green arrow is made by: --color ARROW#00FF00
[--zoom factor]
Zoom the graphics by the given amount. The factor must be > 0
[-n|--font FONTTAG:size:[font]]
This lets you customize which font to use for the various text
elements on the RRD graphs. 
DEFAULT sets the default value for all
elements, 
TITLE for the title, AXIS for the axis labels, UNITfor the vertical unit label, 
LEGEND for the graph legend.
Use Times for the title: --font TITLE:13:/usr/lib/fonts/times.ttf
If you do not give a font string you can modify just the sice of the default font:
--font TITLE:13:.
If you specify the size 0 then you can modify just the font without touching
the size. This is especially usefull for altering the default font without
resetting the default fontsizes: 
--font DEFAULT:0:/usr/lib/fonts/times.ttf.
RRDtool comes with a preset default font. You can set the environment
variable 
RRD_DEFAULT_FONT if you want to change this.
Truetype fonts are only supported for PNG output. See below.
[-R|--font-render-mode {normal,light,mono}]
This lets you customize the strength of the font smoothing,
or disable it entirely using 
mono. By default, normalfont smoothing is used.
[-B|--font-smoothing-threshold size]
This specifies the largest font size which will be rendered
bitmapped, that is, without any font smoothing. By default,
no text is rendered bitmapped.
[-E|--slope-mode]
RRDtool graphs are composed of stair case curves by default. This is in line with
the way RRDtool calculates its data. Some people favor a more 'organic' look
for their graphs even though it is not all that true.
[-a|--imgformat PNG|SVG|EPS|PDF]
Image format for the generated graph. For the vector formats you can
choose among the standard Postscript fonts Courier-Bold,
Courier-BoldOblique, Courier-Oblique, Courier, Helvetica-Bold,
Helvetica-BoldOblique, Helvetica-Oblique, Helvetica, Symbol,
Times-Bold, Times-BoldItalic, Times-Italic, Times-Roman, and ZapfDingbats.
[-i|--interlaced]
If images are interlaced they become visible on browsers more quickly.
[-g|--no-legend]
Suppress generation of the legend; only render the graph.
[-F|--force-rules-legend]
Force the generation of HRULE and VRULE legends even if those HRULE or
VRULE will not be drawn because out of graph boundaries (mimics
behaviour of pre 1.0.42 versions).
[-T|--tabwidth value]
By default the tab-width is 40 pixels, use this option to change it.
[-b|--base value]
If you are graphing memory (and NOT network traffic) this switch
should be set to 1024 so that one Kb is 1024 byte. For traffic
measurement, 1 kb/s is 1000 b/s.
Data and variables DEF:vname=rrdfile:ds-name:CF[:step=step][:start=time][:end=time]
CDEF:vname=RPN expression
VDEF:vname=RPN expression
You need at least one DEF statement to generate anything. The
other statements are useful but optional.
See 
././rrdgraph_data.htmlthe rrdgraph_data manpage  and ././rrdgraph_rpn.htmlthe rrdgraph_rpn manpage  for the exact format.
Graph and print elements You need at least one graph element to generate an image and/or
at least one print statement to generate a report.
See 
././rrdgraph_graph.htmlthe rrdgraph_graph manpage  for the exact format.
SEE ALSO 
././rrdgraph.htmlthe rrdgraph manpage  gives an overview of how rrdtool graph works.
././rrdgraph_data.htmlthe rrdgraph_data manpage  describes DEF,CDEF and VDEF in detail.
././rrdgraph_rpn.htmlthe rrdgraph_rpn manpage  describes the RPN language used in the ?DEF statements.
././rrdgraph_graph.htmlthe rrdgraph_graph manpage  page describes all of the graph and print functions.
Make sure to read ././rrdgraph_examples.htmlthe rrdgraph_examples manpage  for tips&tricks.
AUTHOR 
Program by Tobias Oetiker < mailto:oetiker@ee.ethz.choetiker@ee.ethz.ch >
This manual page by Alex van den Bogaerdt < mailto:alex@ergens.op.het.netalex@ergens.op.het.net >
