====== Gnuplot: Frequently Asked Questions ======

  * http://stackoverflow.com/questions/tagged/gnuplot -- Newest 'gnuplot' Questions - Stack Overflow
  * http://lowrank.net/gnuplot/index-e.html -- Not so Frequently Asked Questions.

===== Inofficial Gnuplot FAQ =====

This is an inofficial gnuplot FAQ (yes, its my personal one).

  * [[https://stackoverflow.com/questions/19412382/gnuplot-line-types|Gnuplot line types]] [(https://web.archive.org/web/20210401201439/https://stackoverflow.com/questions/19412382/gnuplot-line-types)]
  * [[https://stackoverflow.com/questions/67232200/consistent-fonts-in-gnuplot|Consistent fonts in gnuplot?]] [(https://web.archive.org/web/20210517094855/https://stackoverflow.com/questions/67232200/consistent-fonts-in-gnuplot)]
  * [[http://stackoverflow.com/questions/12224567/mutiple-fit-lines-on-same-plot-in-gnuplot|Mutiple fit lines on same plot in gnuplot?]] [(https://web.archive.org/web/20170327005502/https://stackoverflow.com/questions/12224567/mutiple-fit-lines-on-same-plot-in-gnuplot)]
  * [[http://stackoverflow.com/questions/23586904/fitting-a-function-with-multiple-data-sets-using-gnuplot|How to fit a function with multiple data sets using gnuplot]]
  * [[#How can I make a gnuplot script an executable file?]]
  * [[#How do I change the datafield separator?]]
  * [[#How do I change decimal separator?]]
  * [[#How do I export a plot as list of ASCII-data samples?]]
  * [[#How to change plot device/output media?]]
  * [[#How do I change output format of numbers?]]
  * [[#Where can I find the official gnuplot FAQ?]]
  * [[https://wiki.geany.org/config/gnuplot|How to add Gnuplot color syntax support to Geany editor?]]
  * [[#How do I change background color of screen and/or graph?]]
  * [[#How to change linestyle (e.g. line width) for a set of lines?]]
  * [[#How to set line colors to MATLAB default colors?]]
  * [[#How can I add a watermark?]]
  * [[#How to plot multiple y-axes?]]
  * [[#Is there an overview about the predefined gnuplot colors?]]

~~REFNOTES~~

----

=== Where can I find the official gnuplot FAQ? ===

Look [[http://www.gnuplot.info/faq/faq.html|here]]. -- <wrap tip>Note that there are also some [[http://t16web.lanl.gov/Kawano/gnuplot/index-e.html|not so Frequently Asked Questions]].</wrap>

=== How can I make a gnuplot script an executable file? ===

Add the shebang to the first line of your script [(http://www.cyberciti.biz/tips/finding-bash-perl-python-portably-using-env.html)]
<code gnuplot>
#!/usr/bin/env gnuplot
plot sin(x) with lines
</code>

~~REFNOTES~~

=== How do I change the datafield separator? ===

E.g. to read in csv (comma-separated value) files written by spreadsheet programs.
<code gnuplot>
set datafile separator ","
</code>

=== How do I change decimal separator? ===
<code gnuplot>
set decimalsign ','                     # set separator to ','
#set decimalsign locale                 # get separator from system locale settings
#set decimalsign locale "en_GB.utf8"    # set separator to '.' by overriding system locale
#set decimalsign locale "de_DE.utf8"    # set separator to ',' by overriding system locale
</code>

=== How do I export a plot as list of ASCII-data samples? ===
<code gnuplot>
set table
#set terminal table  # some releases of gnuplot need the keyword 'terminal'
set output "temp(u).dat"
set samples 1024
plot [0:1023] f(x*4.8/1024)
</code>

=== How to change plot device/output media? ===
<code gnuplot>
set terminal emf           # Windows Enhanced Meta File
set output "filename.emf"
replot                     # plot again but utilize the new terminal
set term pop               # return to primary terminal
</code>

=== How do I change output format of numbers? ===
<code gnuplot>
set format "%.1f"  # output float numbers with one digit after decimal separator
</code>
<WRAP tip>
Note that format can be limited to axes, e.g.
<code gnuplot>
set format y "%.1f"
</code>
</WRAP>

=== How do I change background color of screen and/or graph? ===
<code gnuplot>
# define screen background color
set object rectangle from screen 0,0 to screen 1,1 fillstyle border fillcolor '#deebf7' behind

# define graph background color
set object rectangle from graph 0,0 to graph 1,1 fillstyle border fillcolor 'white' behind
</code>

=== How to change linestyle (e.g. line width) for a set of lines? ===
<code gnuplot>
set for [i=1:8] style line i linewidth 3
</code>

=== How to set line colors to MATLAB default colors? ===
:Y_FIXME:
<code gnuplot>
# New default Matlab line colors, introduced together with parula (2014b)
set style line 1 lc rgb '#0072bd' # blue
set style line 2 lc rgb '#d95319' # orange
set style line 3 lc rgb '#edb120' # yellow
set style line 4 lc rgb '#7e2f8e' # purple
set style line 5 lc rgb '#77ac30' # green
set style line 6 lc rgb '#4dbeee' # light-blue
set style line 7 lc rgb '#a2142f' # red
</code>

=== How can I add a watermark? ===
<code gnuplot>
# Urheberkennzeichnung
watermark = "`whoami`".'\@'."`hostname`, `date`"
set label watermark at screen 0.01,0.02 font ',6' tc rgb 'gray'
#set bmargin 3.75
</code>

=== How to plot multiple y-axes? ===

  * https://stackoverflow.com/questions/27390317/how-to-plot-multiple-y-axes [(https://web.archive.org/web/20230414210334/https://stackoverflow.com/questions/27390317/how-to-plot-multiple-y-axes)]
  * https://stackoverflow.com/questions/72197168/how-to-plot-several-y-axis-in-the-left-side-using-gnuplot [(https://web.archive.org/web/20230510055740/https://stackoverflow.com/questions/72197168/how-to-plot-several-y-axis-in-the-left-side-using-gnuplot)]

~~REFNOTES~~

=== Is there an overview about the predefined gnuplot colors? ===

  * https://stackoverflow.com/questions/54658674/gnuplot-apply-colornames-from-datafile [(https://web.archive.org/web/20220122005618/https://stackoverflow.com/questions/54658674/gnuplot-apply-colornames-from-datafile)]

~~REFNOTES~~