## MATLAB: Globalsearch not working for a function file.

equationglobalsearch

Hello, Globalsearch is not able to solve my equation in function file. It is giving me an error -‘Supplied objective function must return a scalar value’.I would really appreciate your help. My function file is…

`function F = Trans_eqn_taperedfiber(beta)m = 0;lambda = 1550*10^-3;n1 = 1.45;n2 = 1.43;n3 = 1;k0 = 2*pi/lambda;N = 49000;a=zeros(0,N); b=zeros(0,N); c=zeros(0,N); amax=52.5; amin=40*10^-3; bmax=62.5; bmin=0; for n=1:N; a(n)= ((n-1)*(amax-amin))/(N-1)+amin; b(n)=((n-1)*(bmax-bmin))/(N-1)+bmin; c(n)= a(n)./b(n); end F = [(besselj(m,a.*sqrt(n1^2*k0^2-beta(1).^2))-bessely(m,(a.*sqrt(n1^2*k0^2-beta(1).^2).*c))).*(besselk(m,b.*sqrt( -n3^2*k0^2 + beta(2).^2))-besselj(m,b.*sqrt(n2^2*k0^2- beta(1).^2)))./(besselj(m,a.*sqrt(n1^2*k0^2-beta(1).^2))-besselj(m,b.*sqrt(n2^2*k0^2- beta(1).^2).*c)).*(besselk(m,b.*sqrt( -n3^2*k0^2 + beta(2).^2))-bessely(m,(b.*sqrt(n2^2*k0^2- beta(1).^2)).*c)); (besselj(m,(b.*sqrt(n2^2*k0^2- beta(1).^2)).*c).*bessely(m+1,b.*sqrt(n2^2*k0^2- beta(1).^2)))./(besselj(m+1,b.*sqrt(n2^2*k0^2- beta(1).^2)).*bessely(m+1,(b.*sqrt(n2^2*k0^2- beta(1).^2)).*c))]; F = sqrt(dot(F,F)); end`

My solver is below to call the function file…

`opts = optimoptions(@fmincon,'Algorithm','interior-point');problem = createOptimProblem('fmincon','x0',randn(2,1),... 'objective',@Trans_eqn_taperedfiber,'lb',[5,7.5],'ub',[5,7.5],... 'options',opts); gs = GlobalSearch;[beta] = run(gs,problem);`

Thanks in advance, Chetna.

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