determine of factored form z.m

some code use for dsb matlabe

%determine of factored form
%of rational z-transform
num =input ('type the numerator cofficiente');
den=input ('type the denumerator cofficiente');
[z,p,k]=tf2zp(num,den);
m=abs(p);
disp('zeros are at');disp(z);
disp('poles are at');disp(p);
disp('gain constant');disp(k);
disp('radios of poles');disp(m);
sos=zp2sos(z,p,k);
disp('second order section');disp(real(sos));
zplane(num,den);