Error encountered for numerical integration inside for loop.

So this is the code I'm trying to run -

q=10e8:10000:20e9;

s=length(q);

epso = 8.8 *10.^-12;

epsr=5.7;

ro=3.63*(10.^-3);

epsl = 2.5;

ri=1.13*(10.^-3);

copen = (epso/sqrt(epsr)*log(ro/ri));

cload= (epsl/sqrt(epsr)*log(ro/ri));

t = zeros(1,s);

for f = 1:length(q)

      fun = @(x)(((((besselj(0,(2*pi*q(f))/(3e8))*x*ro)-besselj(0,(2*pi*q(f))/(3e8))*x*ri)).^2)./x).*freload(x,q)));

      y(f) = copen*abs(integral(fun,0,Inf));

      t(f)=(1-y(f))/(1+y(f));

end

plot (q,t);

where the function freload is

function f = freload(x,q)

epsl=3.4;

f=(1./sqrt(epsl-(x.^2))).*(1+exp(-2*1i*2*pi*q./(3e8).*sqrt(epsl-(x.^2))))./((1-exp(-2*1i*2*pi*q/(3e8).*sqrt(epsl-(x.^2)))));

end

The errors I get are as follows -

Error using integralCalc/finalInputChecks (line 515)
Output of the function must be the same size as the input. If FUN is an array-valued integrand, set the
'ArrayValued' option to true.

Error in integralCalc/iterateScalarValued (line 315)
                finalInputChecks(x,fx);

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

Error in integralCalc (line 83)
        [q,errbnd] = vadapt(@AToInfInvTransform,interval);

Error in integral (line 88)
Q = integralCalc(fun,a,b,opstruct);

Error in numint (line 14)
    y(f) = copen*abs(integral(fun,0,Inf));

The program seems to be giving an output for other functions. Any help would be appreciated greatly.

Answer 1

[Walter Roberson]

Your line

        fun = @(x)(((((besselj(0,(2*pi*q(f))/(3e8))*x*ro)-besselj(0,(2*pi*q(f))/(3e8))*x*ri)).^2)./x).*freload(x,q)));

calls freload() passing in all of q, instead of q(f)