computing finite time grammian

Hi When I am trying to find finite grammian I getting the following error:

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>>integral(f,0,1)
Matrix dimensions must agree.

Error in @(tau)expm(A.*tau)*(b*b')*expm(A'.*tau)

Error in integralCalc/iterateScalarValued (line 314)
                fx = FUN(t);

Error in integralCalc/vadapt (line 132)
            [q,errbnd] = iterateScalarValued(u,tinterval,pathlen);

Error in integralCalc (line 75)
        [q,errbnd] = vadapt(@AtoBInvTransform,interval);

Error in integral (line 88)
Q = integralCalc(fun,a,b,opstruct);
 
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My A=[-1/2 0;0 -1]
b=[1;1]
f = @(tau) expm(A.*tau)*(b*b')*expm(A'.*tau)

Thanks in advance

Answer 1

[madhan ravi]

https://www.mathworks.com/matlabcentral/answers/286516-integral-of-controllability-gramian#answer_224073