Error: Trust-region-dogleg algorithm of FSOLVE cannot handle non-square systems; using Levenberg-Marquardt algorithm instead.
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My code has the following error:
Warning: Trust-region-dogleg algorithm of FSOLVE cannot handle non-square systems; using
Levenberg-Marquardt algorithm instead.
> In fsolve (line 298)
In Design (line 16)
Error using levenbergMarquardt (line 16)
Objective function is returning undefined values at initial point. fsolve cannot continue.
Error in fsolve (line 397)
levenbergMarquardt(funfcn,x,verbosity,options,defaultopt,f,JAC,caller, ...
Error in Design (line 16)
neff=fsolve(TM,Nx(i));
Can anyone tell me what is wrong with my below code:
for n=0:1
lamda=1.55;
ko=2.*pi./lamda;
n1TE=1.5100;
n2TE=1.4900;
n4TE=1.4444;
Nx=1.4900:0.0001:1.5100; % as n2<refractive index<n1
b=((n.*pi+atan(sqrt(Nx.^2-n2TE.^2)./sqrt(n1TE.^2-Nx.^2))+atan(sqrt(Nx.^2-n4TE.^2)/sqrt(n1TE.^2-Nx.^2)))./(ko.*sqrt((n1TE.^2-Nx.^2))));
for m=0:1
a=b;
n3TM=1.4895;
n5TM=1.4895;
TM=@(neff) 2.*ko.*a.*sqrt(Nx.^2-neff.^2)-m.*pi-atan((sqrt(neff.^2-n3TM.^2)./sqrt(Nx.^2-neff.^2)).*(Nx.^2./n3TM.^2))-atan((sqrt(neff.^2-n5TM.^2)./sqrt(Nx.^2-neff.^2)).*(Nx.^2./n5TM.^2));
neff=fsolve(TM,Nx);
plot(b,neff)
end
end
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Answers (3)
Stephan
on 7 Mar 2019
Edited: Stephan
on 7 Mar 2019
Hi,
add this line before you call fsolve:
opts = optimoptions(@fsolve,'Algorithm', 'levenberg-marquardt');
Then in your call of fsolve add the options:
neff = fsolve(TM,Nx,opts)
Best regards
Stephan
3 Comments
Stephan
on 7 Mar 2019
For me it works. try:
clear Nx
You have some more problems i guess - try:
n=[0 1];
lamda=1.55;
ko=2.*pi./lamda;
n1TE=1.5100;
n2TE=1.4900;
n4TE=1.4444;
Nx=1.5; % as n2<refractive index<n1
b=((n.*pi+atan(sqrt(Nx.^2-n2TE.^2)./sqrt(n1TE.^2-Nx.^2))+atan(sqrt(Nx.^2-n4TE.^2)/sqrt(n1TE.^2-Nx.^2)))./(ko.*sqrt((n1TE.^2-Nx.^2))));
m = [0 1];
a=b;
n3TM=1.4895;
n5TM=1.4895;
TM=@(neff,m) 2.*ko.*a.*sqrt(Nx.^2-neff.^2)-m.*pi-atan((sqrt(neff.^2-n3TM.^2)./sqrt(Nx.^2-neff.^2)).*(Nx.^2./n3TM.^2))-atan((sqrt(neff.^2-n5TM.^2)./sqrt(Nx.^2-neff.^2)).*(Nx.^2./n5TM.^2));
neff = nan(1,numel(m));
for k = 1:numel(m)
neff(k)=fsolve(@(neff)TM(neff,m(k)),Nx);
end
scatter(b,neff,'or')
hold on
plot(b,neff)
hold off
Ill ch
on 2 Oct 2019
Hi Areez,
i think there are problem with your function. Could you post here your mathematical function on which you want to fit your data? try even this one:
opts = optimoptions(@fsolve,'Algorithm', 'levenberg-marquardt');
clear Nx
n=[0 1];
lamda=1.55;
ko=2.*pi./lamda;
n1TE=1.5100;
n2TE=1.4900;
n4TE=1.4444;
Nx=1.5; % as n2<refractive index<n1
b=((n.*pi+atan(sqrt(Nx.^2-n2TE.^2)./sqrt(n1TE.^2-Nx.^2))+atan(sqrt(Nx.^2-n4TE.^2)/sqrt(n1TE.^2-Nx.^2)))./(ko.*sqrt((n1TE.^2-Nx.^2))));
m = [0 1];
a=b;
n3TM=1.4895;
n5TM=1.4895;
TM=@(neff,m) 2.*ko.*a.*sqrt(Nx.^2-neff.^2)-m.*pi-atan((sqrt(neff.^2-n3TM.^2)./sqrt(Nx.^2-neff.^2)).*(Nx.^2./n3TM.^2))-atan((sqrt(neff.^2-n5TM.^2)./sqrt(Nx.^2-neff.^2)).*(Nx.^2./n5TM.^2));
neff = nan(1,numel(m));
for k = 1:numel(m)
neff(k)=fsolve(@(neff)TM(neff,m(k)),Nx,opts);
end
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