[varnames83, data83]=read_plt('Id_n83_ac_des.plt'); %read all data in matrix as well as data names
CDCG83 = data83(:,strcmp(varnames83,'c(d,cg)'));
CCGCG83 = data83(:,strcmp(varnames83,'c(cg,cg)'));
aDCG83 = data83(:,strcmp(varnames83,'a(d,cg)'));
aCGCG83 = data83(:,strcmp(varnames83,'a(cg,cg)'));
CSCG83 = data83(:,strcmp(varnames83,'c(s,cg)'));
aSCG83 = data83(:,strcmp(varnames83,'a(s,cg)'));
y2183 =aDCG83+1i*2*pi*3e8*CDCG83; % formed by the equation given in Sentaurus user guide
y1183 =aCGCG83+1i*2*pi*3e8*CCGCG83;
ftac83 =3e8/imag(y2183./y1183);
p11=plot(IDS83(1:126)*1e9 ,-ftac83/(1e6),'-','LineWidth',3.0);
pl1.Color= [0 0 1];