extract num and den from matrix transfer function

how to use numerator and denominator (N,D) of the output transfer function yv. where yv is 16 tranfer functions. i want to see N and D and use them in another process.

for i=1:4
    for j=1:4
gvi(i,j)=tf(N(i,:),D(j,:))
yv(i,j)=series(yc,gvi(i,j))

    end

end
    [N,D]= tfdata(yv)%%%% this line doesn't show the content of N and D

Answer 1

[madhan ravi]

Use it inside the loops, preallocation is recommended for the variables.

[msh jgtu]

I tried to use it inside the loop it gives error

[madhan ravi]

 ctr = 0;
 [gvi, yv, N, D] = deal(cell(4*4, 1));
 for ii = 1 : 4
     for jj = 1 : 4
         ctr = ctr + 1;
         gvi{ctr} = tf(N(ii,:),D(jj,:))
         yv{ctr} = series(yc, gvi{ctr})
         [N{ctr}, D{ctr}]= tfdata(yv)
     end
 end
 celldisp(N)
 celldisp(D)

[msh jgtu]

error

Error using tf (line 287)
The values of the "num" and "den" properties must be row vectors or cell arrays of row vectors, where each
vector is nonempty and containing numeric data. Type "help tf.num" or "help tf.den" for more information.

Error in forloop (line 60)
         gvi{ctr} = tf(N(ii,:),D(jj,:))

[madhan ravi]

Without knowing the missing variables , can’t help further.