Provided by: feedgnuplot_1.37-1_all 
NAME
feedgnuplot - General purpose pipe-oriented plotting tool
SYNOPSIS
Simple plotting of piped data:
$ seq 5 | awk '{print 2*$1, $1*$1}'
2 1
4 4
6 9
8 16
10 25
$ seq 5 | awk '{print 2*$1, $1*$1}' |
feedgnuplot --lines --points --legend 0 "data 0" --title "Test plot" --y2 1
--terminal 'dumb 80,40' --exit
Test plot
10 ++------+--------+-------+-------+-------+--------+-------+------*A 25
+ + + + + + + + **#+
| : : : : : : data 0+**A*** |
| : : : : : : :** # |
9 ++.......................................................**.##....|
| : : : : : : ** :# |
| : : : : : : ** # |
| : : : : : :** ##: ++ 20
8 ++................................................A....#..........|
| : : : : : **: # : |
| : : : : : ** : ## : |
| : : : : : ** :# : |
| : : : : :** B : |
7 ++......................................**......##................|
| : : : : ** : ## : : ++ 15
| : : : : ** : # : : |
| : : : :** : ## : : |
6 ++..............................*A.......##.......................|
| : : : ** : ##: : : |
| : : : ** : # : : : |
| : : :** : ## : : : ++ 10
5 ++......................**........##..............................|
| : : ** : #B : : : |
| : : ** : ## : : : : |
| : :** : ## : : : : |
4 ++...............A.......###......................................|
| : **: ##: : : : : |
| : ** : ## : : : : : ++ 5
| : ** : ## : : : : : |
| :** ##B# : : : : : |
3 ++.....**..####...................................................|
| **#### : : : : : : |
| **## : : : : : : : |
B** + + + + + + + +
2 A+------+--------+-------+-------+-------+--------+-------+------++ 0
1 1.5 2 2.5 3 3.5 4 4.5 5
Simple real-time plotting example: plot how much data is received on the wlan0 network
interface in bytes/second (uses bash, awk and Linux):
$ while true; do sleep 1; cat /proc/net/dev; done |
gawk '/wlan0/ {if(b) {print $2-b; fflush()} b=$2}' |
feedgnuplot --lines --stream --xlen 10 --ylabel 'Bytes/sec' --xlabel seconds
DESCRIPTION
This is a flexible, command-line-oriented frontend to Gnuplot. It creates plots from data
coming in on STDIN or given in a filename passed on the commandline. Various data
representations are supported, as is hardcopy output and streaming display of live data. A
simple example:
$ seq 5 | awk '{print 2*$1, $1*$1}' | feedgnuplot
You should see a plot with two curves. The "awk" command generates some data to plot and
the "feedgnuplot" reads it in from STDIN and generates the plot. The "awk" invocation is
just an example; more interesting things would be plotted in normal usage. No commandline-
options are required for the most basic plotting. Input parsing is flexible; every line
need not have the same number of points. New curves will be created as needed.
The most commonly used functionality of gnuplot is supported directly by the script.
Anything not directly supported can still be done with options such as "--set",
"--extracmds" "--style", etc. Arbitrary gnuplot commands can be passed in with
"--extracmds". For example, to turn off the grid, you can pass in "--extracmds 'unset
grid'". Commands "--set" and "--unset" exists to provide nicer syntax, so this is
equivalent to passing "--unset grid". As many of these options as needed can be passed in.
To add arbitrary curve styles, use "--style curveID extrastyle". Pass these more than once
to affect more than one curve.
To apply an extra style to all the curves that lack an explicit "--style", pass in
"--styleall extrastyle". In the most common case, the extra style is "with something". To
support this more simply, you can pass in "--with something" instead of "--styleall 'with
something'". "--styleall" and "--with" are mutually exclusive. Furthermore any curve-
specific "--style" overrides the global "--styleall" or "--with" setting.
Data formats
By default, each value present in the incoming data represents a distinct data point, as
demonstrated in the original example above (we had 10 numbers in the input and 10 points
in the plot). If requested, the script supports more sophisticated interpretation of input
data
Domain selection
If "--domain" is passed in, the first value on each line of input is interpreted as the
X-value for the rest of the data on that line. Without "--domain" the X-value is the line
number, and the first value on a line is a plain data point like the others. Default is
"--nodomain". Thus the original example above produces 2 curves, with 1,2,3,4,5 as the
X-values. If we run the same command with "--domain":
$ seq 5 | awk '{print 2*$1, $1*$1}' | feedgnuplot --domain
we get only 1 curve, with 2,4,6,8,10 as the X-values. As many points as desired can appear
on a single line, but all points on a line are associated with the X-value at the start of
that line.
Curve indexing
By default, each column represents a separate curve. This is fine unless sparse data is to
be plotted. With the "--dataid" option, each point is represented by 2 values: a string
identifying the curve, and the value itself. If we add "--dataid" to the original example:
$ seq 5 | awk '{print 2*$1, $1*$1}' | feedgnuplot --dataid --autolegend
we get 5 different curves with one point in each. The first column, as produced by "awk",
is 2,4,6,8,10. These are interpreted as the IDs of the curves to be plotted. The
"--autolegend" option adds a legend using the given IDs to label the curves. The IDs need
not be numbers; generic strings are accepted. As many points as desired can appear on a
single line. "--domain" can be used in conjunction with "--dataid".
Multi-value style support
Depending on how gnuplot is plotting the data, more than one value may be needed to
represent the range of a single point. Basic 2D plots have 2 numbers representing each
point: 1 domain and 1 range. But if plotting with "--circles", for instance, then there's
an extra range value: the radius. A similar situation exists with "--colormap" where each
point contains the position and the color. There are other gnuplot styles that require
more data (such as error bars), but none of these are directly supported by the script.
They can still be used, however, by specifying the specific style with "--style", and
specifying how many values are needed for each point with "--rangesizeall" or
"--rangesize" or "--extraValuesPerPoint". Those options that specify the range size are
required only for styles not explicitly supported by feedgnuplot; supported styles do the
right thing automatically.
More examples: if making a 2d plot of y error bars where gnuplot expects a (x,y,ydelta)
tuple for each point, you want "--rangesizeall 2" because you have one domain value (x)
and 2 range values (y,ydelta). Gnuplot can also plot lopsided y errorbars by giving a
tuple (x,y,ylow,yhigh). This is similar as before, but you want "--rangesizeall 3"
instead.
3D data
To plot 3D data, pass in "--3d". "--domain" MUST be given when plotting 3D data to avoid
domain ambiguity. If 3D data is being plotted, there are by definition 2 domain values
instead of one (Z as a function of X and Y instead of Y as a function of X). Thus the
first 2 values on each line are interpreted as the domain instead of just 1. The rest of
the processing happens the same way as before.
Time/date data
If the input data domain is a time/date, this can be interpreted with "--timefmt". This
option takes a single argument: the format to use to parse the data. The format is
documented in 'set timefmt' in gnuplot, although the common flags that "strftime"
understands are generally supported. The backslash sequences in the format are not
supported, so if you want a tab, put in a tab instead of \t. Whitespace in the format is
supported. When this flag is given, some other options act a little bit differently:
• "--xlen" is an integer in seconds
• "--xmin" and "--xmax" must use the format passed in to "--timefmt"
Using this option changes both the way the input is parsed and the way the x-axis tics are
labelled. Gnuplot tries to be intelligent in this labelling, but it doesn't always do what
the user wants. The labelling can be controlled with the gnuplot "set format" command,
which takes the same type of format string as "--timefmt". Example:
$ sar 1 -1 |
awk '$1 ~ /..:..:../ && $8 ~/^[0-9\.]*$/ {print $1,$8; fflush()}' |
feedgnuplot --stream --domain
--lines --timefmt '%H:%M:%S'
--set 'format x "%H:%M:%S"'
This plots the 'idle' CPU consumption against time.
Note that while gnuplot supports the time/date on any axis, feedgnuplot currently supports
it only as the x-axis domain. This may change in the future.
Real-time streaming data
To plot real-time data, pass in the "--stream [refreshperiod]" option. Data will then be
plotted as it is received. The plot will be updated every "refreshperiod" seconds. If the
period isn't specified, a 1Hz refresh rate is used. To refresh at specific intervals
indicated by the data, set the refreshperiod to 0 or to 'trigger'. The plot will then only
be refreshed when a data line 'replot' is received. This 'replot' command works in both
triggered and timed modes, but in triggered mode, it's the only way to replot. Look in
"Special data commands" for more information.
To plot only the most recent data (instead of all the data), "--xlen windowsize" can be
given. This will create an constantly-updating, scrolling view of the recent past.
"windowsize" should be replaced by the desired length of the domain window to plot, in
domain units (passed-in values if "--domain" or line numbers otherwise). If the domain is
a time/date via "--timefmt", then "windowsize" is and integer in seconds.
Special data commands
If we are reading streaming data, the input stream can contain special commands in
addition to the raw data. Feedgnuplot looks for these at the start of every input line. If
a command is detected, the rest of the line is discarded. These commands are
"replot"
This command refreshes the plot right now, instead of waiting for the next refresh
time indicated by the timer. This command works in addition to the timed refresh, as
indicated by "--stream [refreshperiod]".
"clear"
This command clears out the current data in the plot. The plotting process continues,
however, to any data following the "clear".
"exit"
This command causes feedgnuplot to exit.
Hardcopy output
The script is able to produce hardcopy output with "--hardcopy outputfile". The output
type can be inferred from the filename, if .ps, .eps, .pdf, .svg or .png is requested. If
any other file type is requested, "--terminal" must be passed in to tell gnuplot how to
make the plot.
Self-plotting data files
This script can be used to enable self-plotting data files. There are 2 ways of doing
this: with a shebang (#!) or with inline perl data.
Self-plotting data with a #!
A self-plotting, executable data file "data" is formatted as
$ cat data
#!/usr/bin/feedgnuplot --lines --points
2 1
4 4
6 9
8 16
10 25
12 36
14 49
16 64
18 81
20 100
22 121
24 144
26 169
28 196
30 225
This is the shebang (#!) line followed by the data, formatted as before. The data file can
be plotted simply with
$ ./data
The caveats here are that on Linux the whole #! line is limited to 127 characters and that
the full path to feedgnuplot must be given. The 127 character limit is a serious
limitation, but this can likely be resolved with a kernel patch. I have only tried on
Linux 2.6.
Self-plotting data with perl inline data
Perl supports storing data and code in the same file. This can also be used to create
self-plotting files:
$ cat plotdata.pl
#!/usr/bin/perl
use strict;
use warnings;
open PLOT, "| feedgnuplot --lines --points" or die "Couldn't open plotting pipe";
while( <DATA> )
{
my @xy = split;
print PLOT "@xy\n";
}
__DATA__
2 1
4 4
6 9
8 16
10 25
12 36
14 49
16 64
18 81
20 100
22 121
24 144
26 169
28 196
30 225
This is especially useful if the logged data is not in a format directly supported by
feedgnuplot. Raw data can be stored after the __DATA__ directive, with a small perl script
to manipulate the data into a useable format and send it to the plotter.
ARGUMENTS
• --"[no]domain"
If enabled, the first element of each line is the domain variable. If not, the point
index is used
• --"[no]dataid"
If enabled, each data point is preceded by the ID of the data set that point
corresponds to. This ID is interpreted as a string, NOT as just a number. If not
enabled, the order of the point is used.
As an example, if line 3 of the input is "0 9 1 20" then
• "--nodomain --nodataid" would parse the 4 numbers as points in 4 different curves
at x=3
• "--domain --nodataid" would parse the 4 numbers as points in 3 different curves at
x=0. Here, 0 is the x-variable and 9,1,20 are the data values
• "--nodomain --dataid" would parse the 4 numbers as points in 2 different curves at
x=3. Here 0 and 1 are the data IDs and 9 and 20 are the data values
• "--domain --dataid" would parse the 4 numbers as a single point at x=0. Here 9 is
the data ID and 1 is the data value. 20 is an extra value, so it is ignored. If
another value followed 20, we'd get another point in curve ID 20
• "--[no]3d"
Do [not] plot in 3D. This only makes sense with "--domain". Each domain here is an
(x,y) tuple
• --"timefmt [format]"
Interpret the X data as a time/date, parsed with the given format
• "--colormap"
Show a colormapped xy plot. Requires extra data for the color. zmin/zmax can be used
to set the extents of the colors. Automatically sets the "--rangesize".
• "--stream [period]"
Plot the data as it comes in, in realtime. If period is given, replot every period
seconds. If no period is given, replot at 1Hz. If the period is given as 0 or
'trigger', replot only when the incoming data dictates this. See the "Real-time
streaming data" section of the man page.
• "--[no]lines"
Do [not] draw lines to connect consecutive points
• "--[no]points"
Do [not] draw points
• "--circles"
Plot with circles. This requires a radius be specified for each point. Automatically
sets the "--rangesize". "Not" supported for 3d plots.
• "--title xxx"
Set the title of the plot
• "--legend curveID legend"
Set the label for a curve plot. Use this option multiple times for multiple curves.
With "--dataid", curveID is the ID. Otherwise, it's the index of the curve, starting
at 0
• "--autolegend"
Use the curve IDs for the legend. Titles given with "--legend" override these
• "--xlen xxx"
When using "--stream", sets the size of the x-window to plot. Omit this or set it to 0
to plot ALL the data. Does not make sense with 3d plots. Implies "--monotonic"
• "--xmin/xmax/ymin/ymax/y2min/y2max/zmin/zmax xxx"
Set the range for the given axis. These x-axis bounds are ignored in a streaming plot.
The y2-axis bound do not apply in 3d plots. The z-axis bounds apply only to 3d plots
or colormaps.
• "--xlabel/ylabel/y2label/zlabel xxx"
Label the given axis. The y2-axis label does not apply to 3d plots while the z-axis
label applies only to 3d plots.
• "--y2 xxx"
Plot the data specified by this curve ID on the y2 axis. Without "--dataid", the ID is
just an ordered 0-based index. Does not apply to 3d plots. Can be passed multiple
times, or passed a comma-separated list. By default the y2-axis curves look the same
as the y-axis ones. I.e. the viewer of the resulting plot has to be told which is
which via an axes label, legend, etc. Prior to version 1.25 of feedgnuplot the curves
plotted on the y2 axis were drawn with a thicker line. This is no longer the case, but
that behavior can be brought back by passing something like
--y2 curveid --style curveid 'linewidth 3'
• "--histogram curveID"
Set up a this specific curve to plot a histogram. The bin width is given with the
"--binwidth" option (assumed 1.0 if omitted). "--histogram" does not touch the drawing
style. It is often desired to plot these with boxes, and this must be explicitly
requested by "--with boxes". This works with "--domain" and/or "--stream", but in
those cases the x-value is used only to cull old data because of "--xlen" or
"--monotonic". I.e. the x-values are not drawn in any way. Can be passed multiple
times, or passed a comma- separated list
• "--binwidth width"
The width of bins when making histograms. This setting applies to ALL histograms in
the plot. Defaults to 1.0 if not given.
• "--histstyle style"
Normally, histograms are generated with the 'smooth frequency' gnuplot style.
"--histstyle" can be used to select different "smooth" settings (see the gnuplot "help
smooth" page for more info). Allowed values are 'frequency' (the default), 'unique',
'cumulative' and 'cnormal'. 'unique' indicates whether a bin has at least one item in
it: instead of counting the items, it'll always report 0 or 1. 'cumulative' is the
integral of the 'frequency' histogram. 'cnormal' is like 'cumulative', but rescaled to
end up at 1.0. Note that there's no normalized 'frequency' option because gnuplot does
not provide one.
"help smooth"
• "--style curveID style"
Additional styles per curve. With "--dataid", curveID is the ID. Otherwise, it's the
index of the curve, starting at 0. Use this option multiple times for multiple curves.
"--styleall" does not apply to curves that have a "--style"
• "--curvestyle curveID"
Synonym for "--style"
• "--styleall xxx"
Additional styles for all curves that have no "--style". This is overridden by any
applicable "--style". Exclusive with "--with".
• "--curvestyleall xxx"
Synonym for "--styleall"
• "--with xxx"
Same as "--styleall", but prefixed with "with". Thus
--with boxes
is equivalent to
--styleall 'with boxes'
Exclusive with "--styleall".
• "--extracmds xxx"
Additional commands to pass on to gnuplot verbatim. These could contain extra global
styles for instance. Can be passed multiple times.
• "--set xxx"
Additional 'set' commands to pass on to gnuplot verbatim. "--set 'a b c'" will result
in gnuplot seeing a "set a b c" command. Can be passed multiple times.
• "--unset xxx"
Additional 'unset' commands to pass on to gnuplot verbatim. "--unset 'a b c'" will
result in gnuplot seeing a "unset a b c" command. Can be passed multiple times.
• "--equation xxx"
Gnuplot can plot both data and symbolic equations. "feedgnuplot" generally plots data,
but with this option can plot symbolic equations also. This is generally intended to
augment data plots, since for equation-only plots you don't need "feedgnuplot".
"--equation" can be passed multiple times for multiple equations. The given strings
are passed to gnuplot directly without any thing added or removed, so styling and such
should be applied in the string. A basic example:
seq 100 | awk '{print $1/10, $1/100}' |
feedgnuplot --with 'lines lw 3' --domain --ymax 1
--equation 'sin(x)/x' --equation 'cos(x)/x with lines lw 4'
Here I plot the incoming data (points along a line) with the given style (a line with
thickness 3), and I plot two damped sinusoids on the same plot. The sinusoids are not
affected by "feedgnuplot" styling, so their styles are set separately, as in this
example. More complicated example:
seq 360 | perl -nE '$th=$_/360 * 3.14*2; $c=cos($th); $s=sin($th); say "$c $s"' |
feedgnuplot --domain --square
--set parametric --set "trange [0:2*3.14]" --equation "sin(t),cos(t)"
Here the data I generate is points along the unit circle. I plot these as points, and
I also plot a true circle as a parametric equation.
• "--square"
Plot data with aspect ratio 1. For 3D plots, this controls the aspect ratio for all 3
axes
• "--square_xy"
For 3D plots, set square aspect ratio for ONLY the x,y axes
• "--hardcopy xxx"
If not streaming, output to a file specified here. Format inferred from filename,
unless specified by "--terminal"
• "--terminal xxx"
String passed to 'set terminal'. No attempts are made to validate this. "--hardcopy"
sets this to some sensible defaults if --hardcopy is given .png, .pdf, .ps, .eps or
.svg. If any other file type is desired, use both "--hardcopy" and "--terminal"
• "--maxcurves xxx"
The maximum allowed number of curves. This is 100 by default, but can be reset with
this option. This exists purely to prevent perl from allocating all of the system's
memory when reading bogus data
• "--monotonic"
If "--domain" is given, checks to make sure that the x- coordinate in the input data
is monotonically increasing. If a given x-variable is in the past, all data currently
cached for this curve is purged. Without "--monotonic", all data is kept. Does not
make sense with 3d plots. No "--monotonic" by default. The data is replotted before
being purged
• "--rangesize curveID xxx"
The options "--rangesizeall", "--rangesize" and "--extraValuesPerPoint" set the number
of values are needed to represent each point being plotted (see "Multi-value style
support" above). These options are only needed if unknown styles are used, with
"--styleall" or "--with" for instance.
"--rangesize" is used to set how many values are needed to represent the range of a
point for a particular curve. This overrides any defaults that may exist for this
curve only.
• "--rangesizeall xxx"
Like "--rangesize", but applies to all the curves.
"--extraValuesPerPoint xxx"
Like "--rangesizeall", but instead of overriding the default, adds to it. For example,
if plotting non-lopsided y errorbars gnuplot wants (x,y,ydelta) tuples. These can be
specified both with "--rangesizeall 2" (because there are 2 range values) or
"--extraValuesPerPoint 1" (because there's 1 more value than usual).
This option is only needed if unknown styles are used, with "--styleall" or "--with"
for instance.
• "--dump"
Instead of printing to gnuplot, print to STDOUT. Very useful for debugging. It is
possible to send the output produced this way to gnuplot directly.
• "--exit"
This controls the details of what happens when the input data is exhausted, or when
some part of the "feedgnuplot" pipeline is killed. This option does different things
depending on whether "--stream" is active, so read this closely.
With interactive gnuplot terminals (qt, x11, wxt), the plot windows live in a separate
process from the main "gnuplot" process. It is thus possible for the main "gnuplot"
process to exit, while leaving the plot windows up (a caveat is that such decapitated
windows aren't interactive). To be clear, there are 3 possible states:
Alive: "feedgnuplot", "gnuplot" alive, plot window process alive, no shell prompt
(shell busy with "feedgnuplot")
Half-alive: "feedgnuplot", "gnuplot" dead, plot window process alive (but non-
interactive), shell prompt available
Dead: "feedgnuplot", "gnuplot" dead, plot window process dead, shell prompt available
The "--exit" option controls the details of this behavior. The possibilities are:
No "--stream", input pipe is exhausted (all data read in)
default; no "--exit"
Alive. Need to Ctrl-C to get back into the shell
"--exit"
Half-alive. Non-interactive prompt up, and the shell accepts new commands.
Without "--stream" the goal is to show a plot, so a Dead state is not useful
here.
"--stream", input pipe is exhausted (all data read in) or the "feedgnuplot" process
terminated
default; no "--exit"
Alive. Need to Ctrl-C to get back into the shell
"--exit"
Dead. No plot is shown, and the shell accepts new commands. With "--stream"
the goal is to show a plot as the data comes in, which we have been doing. Now
that we're done, we can clean up everything.
Note that one usually invokes "feedgnuplot" as a part of a shell pipeline:
$ write_data | feedgnuplot
If the user terminates this pipeline with ^C, then all the processes in the pipeline
receive SIGINT. This normally kills "feedgnuplot" and all its "gnuplot" children, and
we let this happen unless "--stream" and no "--exit". If "--stream" and no "--exit",
then we ignore the first ^C. The data feeder dies, and we behave as if the input data
was exhausted. A second ^C kills us also.
• "--geometry"
If using X11, specifies the size, position of the plot window
• "--version"
Print the version and exit
RECIPES
Basic plotting of piped data
$ seq 5 | awk '{print 2*$1, $1*$1}'
2 1
4 4
6 9
8 16
10 25
$ seq 5 | awk '{print 2*$1, $1*$1}' |
feedgnuplot --lines --points --legend 0 "data 0" --title "Test plot" --y2 1
Realtime plot of network throughput
Looks at wlan0 on Linux.
$ while true; do sleep 1; cat /proc/net/dev; done |
gawk '/wlan0/ {if(b) {print $2-b; fflush()} b=$2}' |
feedgnuplot --lines --stream --xlen 10 --ylabel 'Bytes/sec' --xlabel seconds
Realtime plot of battery charge in respect to time
Uses the result of the "acpi" command.
$ while true; do acpi; sleep 15; done |
perl -nE 'BEGIN{ $| = 1; } /([0-9]*)%/; say join(" ", time(), $1);' |
feedgnuplot --stream --ymin 0 --ymax 100 --lines --domain --xlabel 'Time' --timefmt '%s' --ylabel "Battery charge (%)"
Realtime plot of temperatures in an IBM Thinkpad
Uses "/proc/acpi/ibm/thermal", which reports temperatures at various locations in a
Thinkpad.
$ while true; do cat /proc/acpi/ibm/thermal | awk '{$1=""; print}' ; sleep 1; done |
feedgnuplot --stream --xlen 100 --lines --autolegend --ymax 100 --ymin 20 --ylabel 'Temperature (deg C)'
Plotting a histogram of file sizes in a directory, granular to 10MB
$ ls -l | awk '{print $5/1e6}' |
feedgnuplot --histogram 0 --with boxes
--binwidth 10 --set 'style fill solid'
--ymin 0 --xlabel 'File size (MB)' --ylabel Frequency
ACKNOWLEDGEMENT
This program is originally based on the driveGnuPlots.pl script from Thanassis Tsiodras.
It is available from his site at
<http://users.softlab.ece.ntua.gr/~ttsiod/gnuplotStreaming.html>
REPOSITORY
<https://github.com/dkogan/feedgnuplot>
AUTHOR
Dima Kogan, "<dima@secretsauce.net>"
LICENSE AND COPYRIGHT
Copyright 2011-2012 Dima Kogan.
This program is free software; you can redistribute it and/or modify it under the terms of
either: the GNU General Public License as published by the Free Software Foundation; or
the Artistic License.
See http://dev.perl.org/licenses/ for more information.