Error: Operator '*' is not supported for operands of type 'function_handle'.

This is my code:

cb = 1/5.25; %reverse of aspect ratio
cla = 2*pi; %the slope of lift vs aoa
aa = 5*pi/180; % radiant value of 5 degree
N = [3 5 7]; %list of possible N value
syms a1 a2 a3 a4 a5 a6 a7
A = [a1 a2 a3 a4 a5 a6 a7]; %list of possible An
eqn = A; %list of possible equations
for i = 1:3 %3 possible N values
    counter = N(i); %how many A s would there be
    Acou = A(1:counter); %set up necessary storage space
    anslist = Acou; %set up necessary storage space
    eqncou = eqn(1:counter); %how many equation would there be
    spandiv = 1/(counter+1); %split up the 90 degree by number of equations
    solved = Acou; %set up necessary storage space
    for j = 1:counter %number of possible angle values
        theta = spandiv*j; %angle value, 1/3, 2/3, 3/3 of 90 degree etc.
        temp = 0; %set up necessary storage space
        sym(temp); %set up necessary storage space
        for k = 1:counter %number of An
            anslist(k) = A(k)*(sinpi(k*theta)+0.25*cb*cla*k*(sinpi(k*theta)/sinpi(theta))); %each of the An expression for one angle value
            temp = temp + anslist(k); %summing all An expression
        end
        eqncou(j) = temp == 0.25*cb*cla*aa; %turn into equation
    end
    Asol = vpasolve(eqncou,Acou); %solve them
    %
    if counter == 3
        solved(1) = Asol.a1;
        solved(2) = Asol.a2;
        solved(3) = Asol.a3;
    elseif counter == 5
        solved(1) = Asol.a1;
        solved(2) = Asol.a2;
        solved(3) = Asol.a3;
        solved(4) = Asol.a4;
        solved(5) = Asol.a5;
    elseif counter == 7
        solved(1) = Asol.a1;
        solved(2) = Asol.a2;
        solved(3) = Asol.a3;
        solved(4) = Asol.a4;
        solved(5) = Asol.a5;
        solved(6) = Asol.a6;
        solved(7) = Asol.a7;
    end
    temp = 0;
    sym(temp);
    for j = 1:counter
        eqn1 = @(theta) solved(j)*sinpi(j*theta);
        temp = @(theta) temp + eqn1;
    end
    clbase = temp;
    cL = @(theta) 4*5.25*clbase*-0.5*sin(theta);
    integral(cL,-1*pi/2,pi/2)
    %}
end 

The error is in the line

    cL = @(theta) 4*5.25*clbase*-0.5*sin(theta);

in the form of:

Operator '*' is not supported for operands of type 'function_handle'.

Error in ae515hw1>@(theta)4*5.25*clbase*-0.5*sin(theta) (line 57)

cL = @(theta) 4*5.25*clbase*-0.5*sin(theta);

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);

Error in ae515hw1 (line 58)

integral(cL,-1*pi/2,pi/2)

Does anyone know how to resolve this?

Answer 1

[Torsten]

cb = 1/5.25; %reverse of aspect ratio
cla = 2*pi; %the slope of lift vs aoa
aa = 5*pi/180; % radiant value of 5 degree
N = [3 5 7]; %list of possible N value
syms a1 a2 a3 a4 a5 a6 a7
A = [a1 a2 a3 a4 a5 a6 a7]; %list of possible An
eqn = A; %list of possible equations
format long
for i = 1:3 %3 possible N values
    counter = N(i); %how many A s would there be
    Acou = A(1:counter); %set up necessary storage space
    anslist = Acou; %set up necessary storage space
    eqncou = eqn(1:counter); %how many equation would there be
    spandiv = 1/(counter+1); %split up the 90 degree by number of equations
    solved = Acou; %set up necessary storage space
    for j = 1:counter %number of possible angle values
        theta = spandiv*j; %angle value, 1/3, 2/3, 3/3 of 90 degree etc.
        temp = 0; %set up necessary storage space
        sym(temp); %set up necessary storage space
        for k = 1:counter %number of An
            anslist(k) = A(k)*(sinpi(k*theta)+0.25*cb*cla*k*(sinpi(k*theta)/sinpi(theta))); %each of the An expression for one angle value
            temp = temp + anslist(k); %summing all An expression
        end
        eqncou(j) = temp == 0.25*cb*cla*aa; %turn into equation
    end
    Asol = vpasolve(eqncou,Acou); %solve them
    %
    if counter == 3
        solved(1) = Asol.a1;
        solved(2) = Asol.a2;
        solved(3) = Asol.a3;
    elseif counter == 5
        solved(1) = Asol.a1;
        solved(2) = Asol.a2;
        solved(3) = Asol.a3;
        solved(4) = Asol.a4;
        solved(5) = Asol.a5;
    elseif counter == 7
        solved(1) = Asol.a1;
        solved(2) = Asol.a2;
        solved(3) = Asol.a3;
        solved(4) = Asol.a4;
        solved(5) = Asol.a5;
        solved(6) = Asol.a6;
        solved(7) = Asol.a7;
    end
    clbase = @(theta)sum(double(solved(1:counter)).*sinpi((1:counter).*theta));
    cL = @(theta)4*5.25*clbase(theta).*(-0.5)*sin(theta);
    integral(cL,-1*pi/2,pi/2,'ArrayValued',true)
end 

ans = 
   0.034892168583369

ans = 
   0.034816069810405

ans = 
   0.034856820993593

[JingChong Ning]

so you just changed the last line of code, right?

[Torsten]

I changed

temp = 0;
sym(temp);
for j = 1:counter
    eqn1 = @(theta) solved(j)*sinpi(j*theta);
    temp = @(theta) temp + eqn1;
end
clbase = temp;
cL = @(theta) 4*5.25*clbase*-0.5*sin(theta);
integral(cL,-1*pi/2,pi/2)

to

clbase = @(theta)sum(double(solved(1:counter)).*sinpi((1:counter).*theta));
cL = @(theta)4*5.25*clbase(theta).*(-0.5)*sin(theta);
integral(cL,-1*pi/2,pi/2,'ArrayValued',true)

and included

format long

before the for-loop.

[Walter Roberson]

With special emphasis on changing 5.25*clbase to 5.25*clbase(theta)

By the way: if you have a number of scalar constants being multiplied and divided, it is more efficient to group them all together before any variable gets involved.

4*5.25*(-0.5) * clbase(theta).*sin(theta)

only has to do scalar multiplications for 4 and 5.25 and -0.5 no matter how large the expression clbase(theta) turns out to be. Whereas if you had (for example) 5.25*clbase(theta)*(-0.5) then the is one multiplication by 5.25 for each value in clbase(theta) and then there would be another multiplication by -0.5 for each element of the previous result -- 2*N multiplications for N = length(clbase(theta)) whereas the 5.25*(-0.5)*clbase(theta) would have 1 multiplication for the 5.25*(-0.5) and then N multiplications (one for each element) for a total of N+1 multiplications instead of 2*N .