error using quad2d

My code is as follows

if true
  Rf=5.4E-3;
Rm=7.1E-3;
g=1;
nf=3;
nm=2;
for a=1:1:nf
  rk(1,a)=sqrt(((pi*(Rf^2)*a)/nf)/pi);
end
c=1;
for b=nf+1:1:nm+nf
  rk(1,b)=sqrt((c*pi*(Rm^2-Rf^2)/nm+pi*(Rf^2))/pi);
  c=c+1;
end
sigma=0.1592;
FS11_l= @(theta,y)(cos(theta).^2).*exp(-(sigma.*2.*((rk(1,1).^2-y.^2).^(1/2)))/cos(theta));
FS11_r= @(theta,y) cos(theta).^2;
S_11l = quad2d (FS11_l, 0,pi/2,0,rk(1,1));  % the first term of S_11 
S_11r= quad2d (FS11_r, 0,pi/2,0,rk(1,1));  % the second term of S_11

end

when running it this is shown: Warning: Matrix is singular to working precision. > In @(theta,y)(cos(theta).^2).*exp(-(sigma.*2.*sqrt((rk(1,1).^2-y.^2)))/cos(theta)) In quad2d>tensor at 343 In quad2d at 167 In Hometask2 at 21 Error using .* Matrix dimensions must agree.

Error in @(theta,y)(cos(theta).^2).*exp(-(sigma.*2.*sqrt((rk(1,1).^2-y.^2)))/cos(theta))

Error in quad2d/tensor (line 349) Z1 = FUN(X(VTSTIDX),Y(VTSTIDX)); NFE = NFE + 1;

Error in quad2d (line 167) [Qsub,esub] = tensor(thetaL,thetaR,phiB,phiT);

Error in Hometask2 (line 21) S_11l = quad2d (FS11_l, 0,pi/2,0,rk(1,1)); % the first term of S_11

Where in the equation is the dimension of the matrix messed up, how to solve this problem?

Answer 1

[Star Strider]

You forgot to vectorise the last division here:

FS11_l= @(theta,y)(cos(theta).^2).*exp(-(sigma.*2.*((rk(1,1).^2-y.^2).^(1/2)))./cos(theta));
                                                                 ADDED ‘.’ —> ^