The procedure to obtain the plots is as follows:

(1) java -jar snoopy2gnuplot.jar BZ_set1.csv data.dat -2 128

(2) gnuplot.exe snoopy2d_BZ_set1.plot

where 
   -- BZ_set1.csv is the name of the simulation trace file.
   -- snoopy2d_BZ_set1.plot is a script.
   -- you need to set the path of gnuplot.