bode_as(num,den)

function bode_as(num,den)

zroots=roots(num);
proots=roots(den);
[iz,jz]=find(abs(zroots)==0); 
numz=length(iz);
[ip,jp]=find(abs(proots)==0); 
nump=length(ip);
pend=numz-nump;
sz=[1:length(zroots)];
sp=[1:length(proots)];
zroots=zroots(setdiff(sz,iz),:);
proots=proots(setdiff(sp,ip),:);


zroots2=abs(zroots)-j*real(zroots)./abs(zroots);
proots2=abs(proots)-j*real(proots)./abs(proots);


zz=ones(size(zroots2,1),3);
zz(:,2)=real(zroots2);
zz(:,3)=imag(zroots2);
pp=-ones(size(proots2,1),3);
pp(:,2)=real(proots2);
pp(:,3)=imag(proots2);


%tracciamento moduli
pp_mag=pp;
zz_mag=zz;
vect=[zz_mag;pp_mag];

vect=sortrows(vect,2);
interval=zeros(1,size(vect,1)+2);
interval(:,[2:(size(vect,1)+1)])=vect(:,2)';
try
interval(1,1)=0.01*vect(1,2);
interval(1,end)=100*vect(end,2);
catch
interval(1,1)=0.01*1;
interval(1,2)=100*1;
end

[g,p]=bode(num,den,interval(1));grid on

y(1)=20*log10(g);
indice=2;
y_old=y(1);
i_old=interval(1);
for i=interval(:,[2:length(interval)-1])
    y(indice)=20*pend*log10(i)+y_old-20*pend*log10(i_old);
    pend=pend+vect(indice-1,1);
    i_old=i;
    y_old=y(indice);
    indice=indice+1;
end
y(indice)=20*pend*log10(interval(end))+y_old-20*pend*log10(i_old);
subplot(2,1,1)
semilogx(interval,y,'r');
hold on;
%plot(interval,y,'go');
grid on

%grid on;
indice=1;
hold on;
[AAA,BBB,CCC,DDD]=tf2ss(num,den);
sys=ss(AAA,BBB,CCC,DDD);

%bodemag(sys);
[m1,m2,m3]=bode(num,den,{interval(1,1),interval(1,end)});
hold on;
plot(m3,20*log10(m1));grid on


clear interval;

%tracciamento fasi
[ii,jj]=find(vect(:,3)<0)
vect(ii,1)=-(vect(ii,1));

for i=1:size(vect,1)
interval(1,indice)=0.1*vect(i,2);
interval(2,indice)=vect(i,1);
indice=indice+1;
interval(1,indice)=vect(i,2);
interval(2,indice)=0;
indice=indice+1;
interval(1,indice)=10*vect(i,2);
interval(2,indice)=-vect(i,1);
indice=indice+1;
end
try
interval=interval';
interval=sortrows(interval,1);
interval=interval';
catch
    interval(:,1)=[0.01*1;0];
interval(:,2)=[100*1;0];
interval=interval';
interval=sortrows(interval,1);
interval=interval';
end

interval=[[0.1*interval(1,1);0] interval [10*interval(1,end);0]];
[g,p,w3]=bode(num,den,interval(1));grid on

pp=p;
x=round(p/90);
p=90*x;

yf(1)=p;
indice=2;
yf_old=yf(1);
i_old=interval(1,1);
pend=0;
for i=interval(1,[2:size(interval,2)-1])
    yf(indice)=45*pend*log10(i)+yf_old-45*pend*log10(i_old);
    pend=pend+interval(2,indice);
    i_old=i;
    yf_old=yf(indice);
    indice=indice+1;
end

yf(indice)=yf_old;
subplot(2,1,2)
semilogx(interval(1,:),yf,'r');
hold on;
%plot(interval(1,:),yf,'go');
%grid on;
[m1,m2,m3]=bode(num,den,{interval(1,1),interval(1,end)});grid on
diff=m2(1)-pp;
m2=m2-diff;
hold on
semilogx(m3,m2);grid on