please use the following instruction
# Download and install gnuplot if you do not have it. You can find the windows installer in the [https://sourceforge.net/projects/gnuplot/files/gnuplot/ gnuplot web site for Files section] The latest version is 5.0.3. # Make .octaverc in your USERPROFILE directory. We can find path of USERPROFILE directory by
>> getenv USERPROFILE
make . octaverc by your favorite text editor and set gnuplot_binary e. g.
gnuplot_binary 'C:\Program Files (x86)\gnuplot\bin\gnuplot,exe'
Please do not forget to quote the path name by single quote (') if name of which has (a) white space(s).
== Octave 4.0.1 on cygwin==