set output'brewster_fit0.ps' set terminal postscript set angle degrees f(x)=c*(tan((x/2)-asin((1/a)*sin(x/2)))**2)/(tan((x/2)+asin((1/a)*sin(x/2)))**2)+b a=1.4 b=0.05 c=1000 set xlabel"kat stopnie" set ylabel"V wolty" fit f(x) 'brewster0.txt' via a,b,c plot 'brewster0.txt', f(x) title sprintf("a=%.3f, b=%.3f, c=%.2f, f(x)", a,b,c)