reset

set encoding iso_8859_1
set title "a über I"
set yrange [0:0.1]
set xlabel "[I in {/Symbol m}A]"
set ylabel "[a in m]"
set grid xtics ytics
set key top left

R = 506e3

f(x) = a*x + b
fit f(x) 'Daten23.txt' us (($1)/R * 1e6):($2) via a,b

plot 'Daten23.txt' us (($1)/R * 1e6):($2) title 'Messwerte' lt 1, \
     f(x) title 'Ausgleichsgerade' lt 3

set output "23.eps"
set term postscript enhanced eps color; replot