Edit the supplied Makefile if necessary (I am always on the lookout for people who test fortranposix and gnuplotfortran out with new compilers and on new platforms - so if you are porting the libraries to *BSD, HP-UX, VMS, Mac OSX Darwin, etc. let me know so that we can spread the joy :)).
Run make.
This will generate a shared library : libgnuplotfortran.so and a few .mod files.
Move the shared library to some place within your LD_LIBRARY_PATH. You may want to make it available to everyone, so place it in a system wide path.
Move the .mod files to some standard location on your system. You may want to make these available to everyone, so place them in a system wide path.
Read the file gnuplot_fortran95_interfaces.f90 to learn about the usage of each function and to obtain the interface - superseded by this manual since ver. 0.2.2..
Append the -lgnuplotfortran -lfortranposix options to your linker and three lines to the code where you want to use the library : use datatypes, use gnuplot_module_data, use gnuplot_moduleYou may also need to specify an addition search path for library files (usually -L), depending upon your fortran compiler.