set xrange[-2.9:2.9]
set yrange[-2.9:2.9]
set size square
set zeroaxis lt -1 lw 1

unset tics

set label "v_A = a" at -2,-2 font "Arial,15"
set label "B_0" at -0.55,2.2 font "Arial,12"

set style arrow 1 size character 2,20 filled linewidth 2
set arrow 1 from -0.2,1.7 to -0.2,2.4 arrowstyle 1

set label "(v_A^2+a^2)^{1/2}" at 1.5,-0.2 font "Arial,10"
set label "v_A, a" at -0.5,1.2 font "Arial,10"
set label "v_T" at -0.2,0.75 font "Arial,10"

plot   "GV-3-3.txt" title "v_g (shear Alfven wave)" with points pt 7 lc "red" ps 2
replot "GV-3-1.txt" with line title "v_{gf} (fast mode)" lc rgb "dark-green" linewidth 5
replot "GV-3-2.txt" with line title "v_{gs} (slow mode)" lc rgb "blue" linewidth 5


set terminal png
set output "GV3.png"
replot