Provided by: feedgnuplot_1.61-1_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
--unset grid --terminal 'dumb 80,40' --exit
Test plot
10 +-----------------------------------------------------------------+ 25
| + + + + + + + *##|
| data 0 ***A*#* |
| ** # |
9 |-+ ** ## |
| ** # |
| ** # |
| ** ## +-| 20
8 |-+ A # |
| ** # |
| ** ## |
| ** # |
| ** B |
7 |-+ ** ## |
| ** ## +-| 15
| ** # |
| ** ## |
6 |-+ *A ## |
| ** ## |
| ** # |
| ** ## +-| 10
5 |-+ ** ## |
| ** #B |
| ** ## |
| ** ## |
4 |-+ A ### |
| ** ## |
| ** ## +-| 5
| ** ## |
| ** ##B# |
3 |-+ ** #### |
| **#### |
| #### |
|## + + + + + + + |
2 +-----------------------------------------------------------------+ 0
1 1.5 2 2.5 3 3.5 4 4.5 5
Here we asked for ASCII plotting, which is useful for documentation.
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.
For a tutorial and a gallery please see the guide at
<https://github.com/dkogan/feedgnuplot/blob/master/guide/guide.org>
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", "--cmds"
"--style", etc. Arbitrary gnuplot commands can be passed in with "--cmds". For example, to
turn off the grid, you can pass in "--cmds '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
We index the curves in one of 3 ways: sequentially, explicitly with a "--dataid" or by
"--vnlog" headers.
By default, each column represents a separate curve. The first column (after any domain)
is curve 0. The next one is curve 1 and so on. 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.
If we're plotting "vnlog" data (<https://www.github.com/dkogan/vnlog>) then we can get the
curve IDs from the vnlog header. Vnlog is a trivial data format where lines starting with
"#" are comments and the first comment contains column labels. If we have such data,
"feedgnuplot --vnlog" can interpret these column labels if the "vnlog" perl modules are
available.
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" or "--vnlog".
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. Many other gnuplot styles require more data: errorbars,
variable colors ("with points palette"), variable sizes ("with points ps variable"),
labels and so on. The feedgnuplot tool itself does not know about all these intricacies,
but they can still be used, by specifying the specific style with "--style", and
specifying how many values are needed for each point with any of "--rangesizeall",
"--tuplesizeall", "--rangesize", "--tuplesize". These options are required only for styles
not explicitly supported by feedgnuplot; supported styles do the right thing
automatically.
Specific example: if making a 2d plot of y error bars, the exact format can be queried by
running "gnuplot" and invoking "help yerrorbars". This tells us that there's a 3-column
form: "x y ydelta" and a 4-column form: "x y ylow yhigh". With 2d plots feedgnuplot will
always output the 1-value domain "x", so the rangesize is 2 and 3 respectively. Thus the
following are equivalent:
$ echo '1 2 0.3
2 3 0.4
3 4 0.5' | feedgnuplot --domain --rangesizeall 2 --with 'yerrorbars'
$ echo '1 2 0.3
2 3 0.4
3 4 0.5' | feedgnuplot --domain --tuplesizeall 3 --with 'yerrorbars'
$ echo '1 2 1.7 2.3
2 3 2.6 3.4
3 4 3.5 4.5' | feedgnuplot --domain --rangesizeall 3 --with 'yerrorbars'
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" and "--binwidth" are integers 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,$8; fflush()}' |
feedgnuplot --stream --domain
--lines --timefmt '%H:%M:%S'
--set 'format x "%H:%M:%S"'
This plots the 'idle' CPU consumption against time.
Note that while gnuplot supports the time/date on any axis, feedgnuplot currently supports
it only as the x-axis domain. This may change in the future.
'using' expressions
We just described how feedgnuplot parses its input data. When passing this data to
gnuplot, each curve is sent independently. The domain appears in the leading columns
followed by "--rangesize" columns to complete each row. Without "--domain", feedgnuplot
explicitly writes out sequential integers. gnuplot then knows how many values it has for
each point, and it knows which style we're using, so it's able to interpret the data
appropriately, and to make the correct plot.
As an example, if gnuplot is passed 2 columns of data, and it is plotting "with points",
it will use column 1 for the x coordinate and column 2 for the y coordinate. This is the
default behavior, but the meaning of each column can be controlled via a "using"
expression in gnuplot (not feedgnuplot; keep reading). The default is sequential
integers, so this example uses "using 1:2" by default. We can flip the meaning of the
columns by passing "using 2:1". Arbitrary expressions may be specified by enclosing each
field in "()", and using "$" to denote each data column. So to use the 2nd column as the x
coordinate and the sum of the two columns as the y coordinate, "using 2:($1+$2)" is
passed. Furthermore, the number of columns can vary. For instance gnuplot can read the
same two columns of data, but produce a plot with the extra column encoding the sum as the
color: "using 1:2:($1+$2) with points palette". Please see the gnuplot documentation for
lots of detail.
That's how gnuplot works. Most of the time, feedgnuplot doesn't pass any "using"
expressions at all, and gnuplot does the default thing. But if we want to do something
fancy, feedgnuplot supports "--using curveID expression" and "--usingall expression". So
we can plot a parabola:
seq 100 | feedgnuplot --lines --usingall '1:($2*$2)'
This is powerful, but there are some things to keep in mind:
• "--using" overrides whatever "using" expression feedgnuplot was going to pass.
feedgnuplot passes a "using" expression only if "--histogram" or "--timefmt" or
"--xticlabels" are given. So if "--using" is given together with any of these, the
user must take care to do the right thing (whatever that means at that time).
• The "--tuplesize" controls the data passed to feedgnuplot and the data then passed to
gnuplot. It does not directly control how gnuplot eventually interprets the data:
"--using" does that. So for instance we can plot color-coded points:
seq 10 | feedgnuplot --with 'points pt 7 palette' --usingall '1:2:2'
Here feedgnuplot read 1 column of data. It defauled to "--tuplesize 2", so it passed 2
columns of data to gnuplot. gnuplot then produced 3 values for each point, and plotted
them as indicated with the "points palette" style.
• You always need a column of data to generate a curve. You might want to use a "using"
expression to plot a time series and its cumulative integral. The "using" expression
can compute the integral, but you must pass in the data twice; once for each curve to
plot:
seq 100 | \
awk '{print $1,$1}' | \
feedgnuplot \
--cmds 'sum=0' \
--cmds 'accum(x) = (sum=sum+x)' \
--using 1 '1:(accum($2))' \
--lines --y2 1
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. If we're
plotting a histogram, then "--xlen" causes a histogram over a moving window to be
computed. The subtlely here is that with a histogram you don't actually see the domain
since only the range is analyzed. But the domain is still there, and can be utilized with
"--xlen". With "--xlen" we can plot only histograms or only non-histograms.
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, .png or .gp is
requested. If any other file type is requested, "--terminal" must be passed in to tell
gnuplot how to make the plot. If "--terminal" is passed in, then the "--hardcopy" argument
only provides the output filename.
The .gp output is special. Instead of asking gnuplot to plot to a particular terminal,
writing to a .gp simply dumps a self-executable gnuplot script into the given file. This
is similar to what "--dump" does, but writes to a file, and makes sure that the file can
be self-executing.
Self-plotting data files
This script can be used to enable self-plotting data files. There are several 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 gnuplot
Running "feedgnuplot --hardcopy plotdata.gp ...." will create a self-executable gnuplot
script in "plotdata.gp"
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
• "--vnlog"
Vnlog is a trivial data format where lines starting with "#" are comments and the
first comment contains column labels. Some tools for working with such data are
available from the "vnlog" project: <https://www.github.com/dkogan/vnlog>. With the
"vnlog" perl modules installed, we can read the vnlog column headers with "feedgnuplot
--vnlog". This replaces "--dataid", and we can do all the normal things with these
headers. For instance "feedgnuplot --vnlog --autolegend" will generate plot legends
for each column in the vnlog, using the vnlog column label in the legend.
• "--[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"
This is a legacy option used to who a colormapped xy plot. It does:
- Adds "palette" to "--curvestyleall"
- Adds 1 to the default "--tuplesize" (if "--tuplesizeall" is not given
- Uses "--zmin", "--zmax" to set the colorbar range
It's clearer to set the relevant options explicitly, but "--colormap" still exists for
compatibility
• "--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"/"--tuplesize". "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". If
we're plotting a histogram, then "--xlen" causes a histogram over a moving window to
be computed. The subtlely here is that with a histogram you don't actually see the
domain since only the range is analyzed. But the domain is still there, and can be
utilized with "--xlen". With "--xlen" we can plot only histograms or only
non-histograms.
• "--xmin/xmax/x2min/x2max/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 x2/y2-axis bounds do not apply in 3d plots. The z-axis bounds apply only to 3d
plots or colormaps. Note that there is no "--xrange" to set both sides at once or
"--xinv" to flip the axis around: anything more than the basics supported in this
option is clearly obtainable by talking to gnuplot, for instance "--set 'xrange
[20:10]'" to set the given inverted bounds.
• "--xlabel/x2label/ylabel/y2label/zlabel/cblabel xxx"
Label the given axis. The x2/y2-axis labels do not apply to 3d plots while the z-axis
label applies only to 3d plots. The "cblabel" applies to the colorbar, if there is
one.
• "--x2/--y2/--x1y2/--x2y1/--x2y2 xxx"
By default data is plotted against the x1 and y1 axes (the left and bottom one
respectively). If we want a particular curve plotted against a different axis, we can
specify that with these options. You pass "--AXIS ID" where "AXIS" defines the axis
("x2" or "y2" or "x1y2" or "x2y1" or "x2y2") and the "ID" is the curve ID. "--x2" is a
synonym for "--x2y1" and "--y2" is a synonym for "--x1y2". The curve ID is an ordered
0-based index or a specific ID if "--dataid" or "--vnlog". None of these apply to 3d
plots. Can be passed multiple times for different curve IDs, multiple IDs can be
passed in as a comma-separated list. By default the curves plotted against the various
axes aren not drawn in any differentiated way: the viewer of the resulting plot has to
be told which is which via an axes label, legend, colors, 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). If a drawing style is not specified for
this curve ("--curvestyle") or all curves ("--with", "--curvestyleall") then the
default histogram style is set: filled boxes with borders. This is what the user
generally wants. 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
domain values are not drawn in any way. Can be passed multiple times, or passed a
comma- separated list
• "--xticlabels"
If given, the x-axis tic labels are not numerical, but are read from the data. This
changes the interpretation of the input data: with "--domain", each line begins with
"x label ....". Without "--domain", each line begins with "label ...". Clearly, the
labels may not contain whitespace. This does not affect the tuple size. This makes
sense only without "--3d". Please see the guide
(<https://github.com/dkogan/feedgnuplot/blob/master/guide/guide.org>) for usage
examples.
• "--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), 'fnormal'
(available in very recent gnuplots), 'unique', 'cumulative' and 'cnormal'. 'fnormal'
is a normalized histogram. '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.
• "--style curveID style"
Additional styles per curve. With "--dataid", curveID is the ID. Otherwise, it's the
index of the curve, starting at 0. curveID can be a comma-separated list of IDs to
which the given style should apply. 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".
• "--every curveID factor"
Decimates the input. Instead of plotting every point in the given curve, plot one
point per factor. This is useful to quickly process huge datasets. For instance, to
plot 1% of the data, pass a factor of 100.
• "--everyall factor"
Decimates the input. This works exactly like "--every", except it applies to all the
curves.
• "--using curveID expression"
Specifies a "using" expression to micromanage the plot. This is a powerful option that
allows gnuplot to interpret the input data in arbitrary ways. A "using" expression
tells gnuplot how to map the input columns of data to tuples expected by the plotting
style. Please see the "'using' expressions" section above for more detail.
• "--usingall expression"
Global "using" expressions. This works exactly like "--using", except it applies to
all the curves.
• "--cmds xxx"
Additional commands to pass on to gnuplot verbatim. These could contain extra global
styles for instance. Can be passed multiple times.
• "--extracmds xxx"
Synonym for "--cmds xxx"
• "--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.
• "--image filename"
Overlays the data on top of a raster image given in "filename". This is passed through
to gnuplot via "--equation", and is not interpreted by "feedgnuplot" other than
checking for existence. Usually images have their origin at the top-left corner, while
plots have it in the bottom-left corner instead. Thus if the y-axis extents are not
specified ("--ymin", "--ymax", "--set 'yrange ...'") this option will also flip around
the y axis to make the image appear properly. Since this option is just a passthrough
to gnuplot, finer control can be achieved by passing in "--equation" and "--set yrange
..." directly.
• "--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 anything 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.
• "--equation-below xxx"
Synonym for "--equation". These are rendered below all the other data.
• "--equation-above xxx"
Like "--equation", but is rendered on top of all the other data.
• "--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". If "--terminal" is given, "--hardcopy" sets only the
output filename.
• "--terminal xxx"
String passed to 'set terminal'. No attempts are made to validate this. "--hardcopy"
sets this to some sensible defaults if "--hardcopy" is set to a filename ending in
".png", ".pdf", ".ps", ".eps" or ".svg". If any other file type is desired, use both
"--hardcopy" and "--terminal"
• "--maxcurves N"
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. This is useful in streaming plots where the incoming data represents
multiple iterations of the same process (repeated simulations of the same period in
time, for instance).
• "--rangesize curveID N"
The options "--rangesizeall" and "--rangesize" 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.
With "--dataid", curveID is the ID. Otherwise, it's the index of the curve, starting
at 0. curveID can be a comma-separated list of IDs to which the given rangesize should
apply.
• "--tuplesize curveID N"
Very similar to "--rangesize", but instead of specifying the range only, this
specifies the whole tuple. For instance if we're plotting circles, the tuplesize is 3:
"x,y,radius". In a 2D plot there's a 1-dimensional domain: "x", so the rangesize is 2:
"y,radius". This dimensionality can be given either way.
• "--rangesizeall N"
Like "--rangesize", but applies to all the curves.
• "--tuplesizeall N"
Like "--tuplesize", but applies to all the curves.
• "--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 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). There are 3 possible states of the polotting pipeline:
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 possibilities are:
No "--stream", all data read in
no "--exit" (default)
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 would not be
useful.
"--stream", all data read in or the "feedgnuplot" process terminated
no "--exit" (default)
Alive. Need to Ctrl-C to get back into the shell. This means that when making
live plots, the first Ctrl-C kills the data feeding process, but leaves the
final plot up for inspection. A second Ctrl-C kills feedgnuplot as well.
"--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"
Specifies the size, position of the plot window. This applies only to the "x11"
gnuplot terminal, and has no effect otherwise. To control the window size for any
other terminal, ask for the terminal explicitly, with the options specifying the size.
For instance "--terminal 'qt size 1024,768'"
• "--version"
Print the version and exit
RECIPES
For a tutorial and a gallery please see the guide at
<https://github.com/dkogan/feedgnuplot/blob/master/guide/guide.org>
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
--binwidth 10
--ymin 0 --xlabel 'File size (MB)' --ylabel Frequency
Plotting a live histogram of the ping round-trip times for the past 20 seconds
$ ping -D 8.8.8.8 |
perl -anE 'BEGIN { $| = 1; }
$F[0] =~ s/[\[\]]//g or next;
$F[7] =~ s/.*=//g or next;
say "$F[0] $F[7]"' |
feedgnuplot --stream --domain --histogram 0 --binwidth 10 \
--xlabel 'Ping round-trip time (s)' \
--ylabel Frequency --xlen 20
Plotting points on top of an existing image
This can be done with "--image":
$ < features_xy.data
feedgnuplot --points --domain --image "image.png"
or with "--equation":
$ < features_xy.data
feedgnuplot --points --domain
--equation '"image.png" binary filetype=auto flipy with rgbimage'
--set 'yrange [:] reverse'
The "--image" invocation is a convenience wrapper for the "--equation" version. Finer
control is available with "--equation".
Here an existing image is given to gnuplot verbatim, and data to plot on top of it is
interpreted by feedgnuplot as usual. "flipy" is useful here because usually the y axis
points up, but when looking at images, this is usually reversed: the origin is the top-
left pixel.
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 2011-2021 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.