Added log form gnuplot showing how to display level-sets.

tomas@tomas-linux:~/Desktop/VU_CPU_MAPA/work_dir$ gnuplot

	G N U P L O T

	Version 4.6 patchlevel 4    last modified 2013-10-02 

	Build System: Linux x86_64

	Copyright (C) 1986-1993, 1998, 2004, 2007-2013

	Thomas Williams, Colin Kelley and many others

	gnuplot home:     http://www.gnuplot.info

	faq, bugs, etc:   type "help FAQ"

	immediate help:   type "help"  (plot window: hit 'h')

Terminal type set to 'wxt'

gnuplot> set cntrparam levels 15

gnuplot> set cntrparam bspline

gnuplot> set contour

gnuplot> splot 'u-00001.gplt'

gnuplot> unset surface

gnuplot> splot 'u-00001.gplt'

gnuplot> set table "test.gplt"

gnuplot> splot 'u-00001.gplt'

gnuplot> unset table

gnuplot> set table "test2.gplt"

gnuplot> plot 'test.gplt' index 10

gnuplot> unset table

gnuplot> plot 'test2.gplt'