Plot your graphs with command line gnuplot
February 12th, 2009 mysurface Posted in Developer, gnuplot | Hits: 223922 | 12 Comments »
gnuplot is a command line driven graph plotter tools for us to generate graphs. The common graphs that we are looking forward to present the resource performance per seconds, hours, days, weeks or months are usually plot graphs, which it consist of lines and dots. gnuplot allows us to read the data from text files which contains values in tabular format.
For example, I have a module that extract raw values into logs based on the specified interval. The result will looks like this (test.dat):
##date time slot_1 slot_2 slot_3 slot_4 slot_5 slot_6 slot_7 slot_8 slot_9 slot_10
06/02/2009 09:16:49 16 6 15 5 14 4 17 3 14 4
06/02/2009 09:16:54 16 8 13 3 15 4 17 4 15 5
06/02/2009 09:16:59 18 8 11 5 15 6 14 3 16 5
06/02/2009 09:17:04 19 6 12 5 18 7 15 5 18 5
06/02/2009 09:17:09 19 7 14 6 16 6 16 6 18 4
06/02/2009 09:17:14 21 7 17 5 19 7 16 4 20 5
06/02/2009 09:17:19 20 5 19 6 17 5 15 3 17 3
06/02/2009 09:17:24 20 6 21 5 18 4 14 4 18 4
06/02/2009 09:17:29 17 5 19 4 16 4 15 4 17 2
gnuplot allows us to create a template describe how our graph outlook. To generate the graph, we just have to execute the template, just like executing bash script.
This is a sample of a gnuplot template that I use to construct a plot graph, (test1.pg)
#!/usr/bin/gnuplot
reset
set terminal png
set xdata time
set timefmt "%d/%m/%Y %H:%M:%S"
set format x "%H:%M"
set xlabel "time"
set ylabel "total actives"
set yrange [0:31]
set title "M7YC Performance per time"
set key reverse Left outside
set grid
set style data linespoints
plot "test.dat" using 1:3 title "slot 1", \
"" using 1:4 title "slot 2", \
"" using 1:5 title "slot 3", \
"" using 1:6 title "slot 4", \
"" using 1:7 title "slot 5", \
"" using 1:8 title "slot 6", \
"" using 1:9 title "slot 7", \
"" using 1:10 title "slot 8", \
"" using 1:11 title "slot 9", \
"" using 1:12 title "slot 10"
#To allow the template to be executable, the first line of the template must add the SHABANG ‘#!/usr/bin/gnuplot’, similar to bash script. And also remember to perform chmod to your template.
chmod +x test1.pgI would like to generate graph that shows the performance value over time, therefore I have to read datetime into my X axis and performance value into my Y axis. First two columns of my data file are datetime, I need to set the xdata as time, the define the time format in the raw data files and at last define the x format to appear in my graph.
set xdata time
set timefmt "%d/%m/%Y %H:%M:%S"
set format x "%H:%M"I would like to display my keys outside the graphs as well as enable the grid to ease the reading.
set key reverse Left outside
set gridThe plot graph I intended to generate consist of lines and dots.
set style data linespointsThe important part is how to define the source of my raw data, how many items I wanted to plot into the graph, as well as giving each item a title. The plot format may vary based on different graph format, but for my case it is
plot [raw_data] using [x value's column in data file]:[y value's column in data files] title [item's name], ...
The plot portion can be shorten into this:
plot "test.dat" u 1:3 t "slot 1", \
"" u 1:4 t "slot 2", \
"" u 1:5 t "slot 3", \
"" u 1:6 t "slot 4", \
"" u 1:7 t "slot 5", \
"" u 1:8 t "slot 6", \
"" u 1:9 t "slot 7", \
"" u 1:10 t "slot 8", \
"" u 1:11 t "slot 9", \
"" u 1:12 t "slot 10"
Execute the template and redirect the binary stream to construct a png file.
./test1.pg > test1.pngtest1.png
gnuplot is far more powerful than what I have illustrate here, you may want to checkout the official website for more info.
P.S. I am using gnuplot v4.2 while writing this.
February 13th, 2009 at 2:25 am
This goes into my del.icio.us collection – I don’t want it now – but I am sure it will come in handy soon. Last time I had to create a graph, I had to use Open Office.
March 25th, 2009 at 5:17 pm
Thank you very much for sharing!
It’s always easier to do something if you have an example.
Thank you.
March 26th, 2009 at 6:58 pm
that look cool. have you tried generating the plot from RRD?
August 31st, 2009 at 9:34 am
Sweet, thanks mate. I need something like this at my work for our weekly votes on the “Chips” at the cafeteria :)
January 20th, 2010 at 5:01 pm
This has solved my problem , this is what
i really want.
January 21st, 2011 at 5:53 am
Hey there just wanted to give you a quick heads up and let you know a few of the pictures aren’t loading properly. I’m not sure why but I think its a linking issue. I’ve tried it in two different browsers and both show the same results.
April 29th, 2011 at 1:43 pm
I’ve bookmarked, Dugg, and I joined the RSS subscription. Thanks! .
November 24th, 2011 at 5:07 am
Hi,
How can we change this script that parameters are taken from command line as in the shell script with using $1,$2
ex:
./test1.pg filename > filename.png
thank you for your considerations
February 23rd, 2012 at 3:10 pm
thank you!! it was very helpful!! :)
March 25th, 2012 at 2:00 pm
It is very useful. I have already bookmarked it.
December 22nd, 2012 at 1:47 am
Amazing …really very helpful to beginners like me.
March 11th, 2013 at 2:44 pm
how to display graph in ns2.34.what is the command for that??