Symbolsk løsning av nodeligninger med Matlab

% Using Kirchoff's current law (KCL) on a source follower configuration
% to find Vout as a function of Vin
% Only Cgd is considered (Zc)
% Kjetil Ullaland

ligning1='(Vout-Vgs)/Zc+gm*Vgs+Vout/Rl=0';
ligning2='(Vgs-Vout)/Zc+(Vgs-Vin)/Rs=0';
ligning1=subs(ligning1,'1/(j*w*C)','Zc');
ligning2=subs(ligning2,'1/(j*w*C)','Zc');
pretty(ligning1);
pretty(ligning2);


disp('Solve for Vgs');
vgs_solved=solve(ligning2,'Vgs');
pretty(simplify(vgs_solved));

disp('Solve for Vout(vin)');
ligning3=subs(ligning1,vgs_solved,'Vgs');
Vout_solved=solve(ligning3,'Vout');
pretty(simplify(Vout_solved))