Hi, please I'd appreciate any support in solving this problem. I am trying to evaluate the double integral given in the following equation.

where,

In the integral, can be assumed constants as their values are known apriori.

Here is my issue, when I try to evaluate this integral, I get error messages about incorrect dimensions for matrix multiplication. I am not sure where this issue is arising from, and I have tried to debug myself all to no avail. It'd great if anyone can help. Here is my code

`% Variables`

R = 0;h = 20;b = 1.2;k = 1.6*10^5;ec = 0.009;x = 0;% Functions

v = @(t) b./sqrt(1 -(ec*cos(t)));fun = @(t,r) r.*log(1 + (k./(r.^2+h^2+R^2+(2.*r.*sqrt(h^2+R^2)*sin(-t+x)))));% Integral evaluation

I = integral2(fun,0,2*pi,0,v);

The error messages I get when I run the above code is as follows:

`Error using * Incorrect dimensions for matrix multiplication. Check that the number of columns in the first matrix matches the number of rows in thesecond matrix. To perform elementwise multiplication, use '.*'.Error in @(e,r)r.*log(1+(k./(r.^2+h^2+Ri^2+(2.*r.*sqrt(h^2+Ri^2)*sin(-e+x)))))Error in integral2Calc>integral2t/tensor (line 237) Z1 = FUN(X(VTSTIDX),Y(VTSTIDX)); NFE = NFE + 1;Error in integral2Calc>integral2t (line 55)[Qsub,esub] = tensor(thetaL,thetaR,phiB,phiT);Error in integral2Calc (line 9) [q,errbnd] = integral2t(fun,xmin,xmax,ymin,ymax,optionstruct);Error in integral2 (line 106) Q = integral2Calc(fun,xmin,xmax,yminfun,ymaxfun,opstruct);`

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