how to get transfer function for this problem?

I am working on following .m file.

 n1=1;d1=1;
n2=1;d2=[1 1];
n3=1;d3=[1 2];
n4=1;d4=[1 3];
n5=4;d5=1;
n6=8;d6=1;
n7=12;d7=1;
nblocks=7;
blkbuild
q=[2 1 -5 0 0;3 2 -6 0 0 ;4 2 -6 3 -7;5 3 0 0 0;6 3 0 0 0;7 4 0 0 0];
input=1; output=4;
[A, B, C, D]=connect(a,b,c,d,q,input,output);
[num,den]=ss2tf(A,B,C,D);
printsys(num,den,'s')

when I get the answer it looks like this:

num/den =

    1.0658e-014 s^2 + 1 s + 3
   --------------------------
   s^3 + 26 s^2 + 179 s + 210

BUT I WANT IT TO LOOK LIKE THIS, HOW CAN I DO IT. THANKS.

num/den =

           1 s + 3
   --------------------------
   s^3 + 26 s^2 + 179 s + 210

[roopa]

n1=[1];

d1=[1];

n2=[1]

d2=[1 1];

n3=[1]

d3=[1 2];

n4=[1]

d4=[1 3];

n5=[4];

d5=[1];

n6=[8];

d6=[1];

n7=12

d7=[1];

nblocks=7;

blkbuild

q=[1 0 0 0 0

2 1 -5 0 0

3 2 -6 0 0

4 2 -6 3 -7

5 3 0 0 0

6 3 0 0 0

7 4 0 0 0]

input=1

output=4

[aa bb cc dd]=connect(a,b,c,d,q,input,output)

[num den]= ss2tf(aa,bb,cc,dd)

printsys(num,den)

[aa bb cc dd]=connect(a,b,c,d,q,input,output)

i am not getting above conversion what is a,b,c,d how it will convert please exaplain each step

Answer 1

[Azzi Abdelmalek]

you have just to remove the first coefficient from num

 num=num(2:end)
 model1=tf(num,den)

[K]

Thanks Azzi,

it works.

Answer 2

[Udita Singh]

blkbuild command is showing an error

how can i resolve this??

close all;
clear all;
n1=1; d1=1;
n2=1; d2=[1 1];
n3=1; d3=[1 2];
n4=1; d4=[1,3];
n5=4; d5=1;
n6=8; d6=1;
n7=12; d7=1;
input=1; 
output=4;
nblocks=7;
blkbuild;
q=[2 1 -5 0 0
   3 2 -6 0 0
   4 3 -7 2 -6
   5 3 0 0 0
   6 3 0 0 0
   7 4 0 0 0];
[aa,bb,cc,dd]=connect(a,b,c,d,q,input,output);
[n,d]=ss2tf(aa,bb,cc,dd);
printsys(n,d,'s')

[Walter Roberson]

What error are you observing? It seems to execute without difficulty.

n1=1; d1=1;
n2=1; d2=[1 1];
n3=1; d3=[1 2];
n4=1; d4=[1,3];
n5=4; d5=1;
n6=8; d6=1;
n7=12; d7=1;
input=1; 
output=4;
nblocks=7;
blkbuild;

State model [a,b,c,d] of the block diagram has 7 inputs and 7 outputs.

q=[2 1 -5 0 0
   3 2 -6 0 0
   4 3 -7 2 -6
   5 3 0 0 0
   6 3 0 0 0
   7 4 0 0 0];
[aa,bb,cc,dd]=connect(a,b,c,d,q,input,output);
[n,d]=ss2tf(aa,bb,cc,dd);
printsys(n,d,'s')

 
num/den = 
 
              s + 3
   --------------------------
   s^3 + 26 s^2 + 179 s + 210

[Udita Singh]

Actually its not its showing me error

can you pls help me because its working perfectly in online matlab