clc;

ug   = -4:0.2:0;

% Kennlinienfeld aus Datenblatt
u100 = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0.05e-3, 0.18e-3, 0.32e-3, 0.52e-3, 0.76e-3, 1.04e-3, 1.38e-3, 1.72e-3, 2.1e-3];
u150 = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0.035e-3, 0.12e-3, 0.24e-3, 0.4e-3, 0.6e-3, 0.82e-3, 1.1e-3, 1.45e-3, 1.84e-3, 2.33e-3, 2.79e-3, 3.3e-3];
u200 = [0, 0, 0, 0, 0, 0, 0.03e-3, 0.1e-3, 0.21e-3, 0.38e-3, 0.59e-3, 0.81e-3, 1.04e-3, 1.36e-3, 1.72e-3, 2.12e-3, 2.59e-3, 3.05e-3, 3.57e-3, 4.05e-3, 4.6e-3];
u250 = [0, 0, 0, 0, 0.09e-3, 0.2e-3, 0.34e-3 0.48e-3, 0.68e-3, 0.93e-3, 1.2e-3, 1.54e-3, 1.89e-3, 2.3e-3, 2.78e-3, 3.25e-3, 3.79e-3, 4.3e-3, 4.82e-3, 5.39e-3, 5.95e-3];
iaSoll = [u100, u150, u200, u250];

% Regressionsanweisung
k = nlinfit(ug,iaSoll,@roehrenfkt,[92.12, 1.015e-3, 50], options);

% Plotten
ia = roehrenfkt(k, ug);
ia = reshape(ia,4,21);
hold on
plot(ug,u100,'color','r')
plot(ug,ia(1,:))
plot(ug,u150,'color','r')
plot(ug,ia(2,:))
plot(ug,u200,'color','r')
plot(ug,ia(3,:))
plot(ug,u250,'color','r')
plot(ug,ia(4,:))
legend('Original','Modell')