matlab optimal control plotting

hi, i did my code

just i need to ( Plot the time history of control gain for 30 sec) can any one help me ?

my code is :

tspan=[0,30];% time span

u=0.175; %maximum it can be 10 degree

%K is control gain

A=[-1.397,1,0,0;-5.47,-3.27,0,0;0,1,0,0;-400,0,400,0];

B=[-0.124;-13.2;0;0];

Q=[1,0,0,0

0,1,0,0

0,0,1,0

0,0,0,1];%Weighting are consider same on the states

R=2;% weighting on inputs

N=[1;1;1;1];

[K,S,e] = lqr(A,B,Q,R,N);

%K is the optimal gain