reset

set title "Hallspannung bei konstantem Strom I_s = 20.5 mA"
set xlabel "[B in T]"
set ylabel "[U_{H} in V]"
set grid xtics ytics
set key top left

f(x) = a*x + b
fit f(x) 'DatenHallInAsIconst.txt' us ($2):($3) via a,b

plot \
'DatenHallInAsIconst.txt' us ($2):($3) notitle lt 1, \
f(x) title "Ausgleichsgerade" lt 3

set output "hallinasiconst.eps"
set term postscript enhanced eps color; replot