the error of not enough input arguments

Hello,

i am trying to run the below code , but it gives me the error of not enough input arguments

can anyone help me

thanks in advance

the code is:

d1= 1545e-9:1e-9:1548e-9;
d2= 1548e-9:0.1e-9:1557e-9;
d3= 1557e-9:1e-9:1575e-9;
d=[d1 d2 d3];
o=b(2,:);
% the begin of apodized DFB
is=length(d);
l=40e-3;
no=1e-5;
pi=22/7;
a=4*log(2);
e=l/ii;
for i1=1:is
    i1
x(i1)=9.19.*( (1/d(i1))-(1e9/1550));
k(i1)=@(z) (pi/d(i1)).*no.*exp(-a.*((z-(l/2))/l).^2);
kt=(pi/1550e-9)*no;
g= 0.98*(4*kt*exp(-kt*l)+0.15);
q(i1)=sqrt(((g-(1j*x(i1)).^(2))+(k(i1).^2)));
dfdz(i1)=@(z,f) [ (1j.*k(i1)).*(f(2))-((g-(1j.*x(i1))).*f(1)); ( -1j.*k(i1).*(f(1)))+((g-(1j.*x(i1))).*f(2)) ];
bc2(i1)=@(fa,fb)[  fa(1)-o(i1); fb(2)  ];
finit(i1)=@(z)[((-1j./k(i1)).*((q(i1).*(((k(i1).*o(i1))./(x(i1).*tanh(l.*q(i1)) + (g.*tanh(l.*q(i1)).*1j) - q(i1).*1j).*cosh((q(i1).*z))+(-(k(i1).*o(i1).*tanh(l.*q(i1)))./(x(i1).*tanh(l.*q(i1)) + g.*tanh(l*q(i1))*1j - q(i1).*1j).*sinh((q(i1).*z)))))+((g-(1j.*x(i1))).*((-(k(i1).*o(i1).*tanh(l.*q(i1)))./(x(i1).*tanh(l.*q(i1)) + g.*tanh(l.*q(i1)).*1j - (q(i1).*1j)).*cosh(q(i1).*z)+((k(i1).*o(i1))./(x(i1).*tanh(l.*q(i1)) + g.*tanh(l.*q(i1)).*1j - q(i1).*1j).*sinh(q(i1).*z))))))));(-(k(i1).*o(i1).*tanh(l.*q(i1)))./(x(i1).*tanh(l.*q(i1)) + g.*tanh(l.*q(i1))*1j - q(i1).*1j).*cosh(q(i1).*z))+((k(i1).*o(i1))./(x(i1).*tanh(l.*q(i1)) + (g.*tanh(l.*q(i1)).*1j) - (q(i1).*1j)).*sinh(q(i1).*z))];
dbstop if error
solinit2(i1)=bvpinit(linspace(0,l),finit(i1));
sol2(i1)=bvp4c(dfdz(i1),bc2(i1),solinit2(i1));
idx2= e:e:l;
u(:,i1)=deval(sol2(i1),idx2(i1));
delta2(i1)=l.*x(i1);
diff2(i1)=d(i1)-(1550e-9);
end

[Alex Mcaulley]

Can you put the complete red errot text?

[Walter Roberson]

k(i1)=@(z) (pi/d(i1)).*no.*exp(-a.*((z-(l/2))/l).^2);

That line creates a function handle and attempts to store it at k(i1) . That will work when i1 is 1, so you are writing to k(1), but it will fail if i1 is anything else. It is not permited to create regular arrays of function handles, only cell arrays of function handles, k{i1} = ...

[Jan]

Walter hits the point. The same for dfdz, bc2, finit

Hint: Avoid "l" (lower case L) as name of a variable. It is confused with 1 (one) too often.

dbstop if error will increase the run time. Use this for debugging only and do not insert it in productive code.

[ayman elashmawy]

Hello

thanks for your reply and i made some modifications but gives the error

Error using bvp4c (line 251)
Unable to solve the collocation equations -- a singular Jacobian encountered.

Error in newcomposite31052019 (line 73)
sol2(i1)=bvp4c(dfdz{i1},bc2{i1},solinit2(i1));

PLEASE can you help me ?

THANKS IN ADVANCE

the code after modifications is:

o=b(2,:);
is=length(d);
L2=40e-3;
no=1e-5;
pi=22/7;
a=4*log(2);
e=L2/ii;
for i1=1:is
    i1
x(i1)=9.19.*( (1/d(i1))-(1e9/1550));
k(i1)=@(z) (pi/d(i1)).*no.*exp(-a.*((z-(L2/2))/L2).^2);
kt=(pi/1550e-9)*no;
g= 0.98*(4*kt*exp(-kt*L2)+0.15);
q(i1)=@(z) sqrt(((g-(1j.*x(i1)).^(2))+(k(i1)^2)));
dfdz{i1}=@(z,f) [ (1j.*k(i1)).*(f(2))-((g-(1j.*x(i1))).*f(1)); ( -1j.*k(i1).*(f(1)))+((g-(1j.*x(i1))).*f(2)) ];
bc2{i1}=@(fa,fb)[  fa(1)-o(i1); fb(2)  ];
finit{i1}=@(z)[((-1j.*(k(i1).^(-1))).*((q(i1).*(((k(i1).*o(i1))./(x(i1).*tanh(L2.*q(i1)) + (g.*tanh(L2.*q(i1)).*1j) - q(i1).*1j).*cosh((q(i1).*z))+(-(k(i1).*o(i1).*tanh(L2.*q(i1)))./(x(i1).*tanh(L2.*q(i1)) + g.*tanh(L2*q(i1))*1j - q(i1).*1j).*sinh((q(i1).*z)))))+((g-(1j.*x(i1))).*((-(k(i1).*o(i1).*tanh(L2.*q(i1)))./(x(i1).*tanh(L2.*q(i1)) + g.*tanh(L2.*q(i1)).*1j - (q(i1).*1j)).*cosh(q(i1).*z)+((k(i1).*o(i1))./(x(i1).*tanh(L2.*q(i1)) + g.*tanh(L2.*q(i1)).*1j - q(i1).*1j).*sinh(q(i1).*z))))))));(-(k(i1).*o(i1).*tanh(L2.*q(i1)))./(x(i1).*tanh(L2.*q(i1)) + g.*tanh(L2.*q(i1))*1j - q(i1).*1j).*cosh(q(i1).*z))+((k(i1).*o(i1))./(x(i1).*tanh(L2.*q(i1)) + (g.*tanh(L2.*q(i1)).*1j) - (q(i1).*1j)).*sinh(q(i1).*z))];
dbstop if error
solinit2(i1)=@(z) bvpinit(linspace(0,L2),finit{i1});
sol2(i1)=bvp4c(dfdz{i1},bc2{i1},solinit2(i1));
idx2= e:e:L2;
u(:,i1)=deval(sol2(i1),idx2(i1));
delta2(i1)=L2.*x(i1);
diff2(i1)=d(i1)-(1550e-9);
end

[Jan]

I cannot run your code due to the missing input data, e.g. b.

q1 and solinit2 still use round parentheses instead or curly braces.

The error message ist clear: The Jacobian is singular. This might be caused by a moistake in the formula, but of course the forum cannot fix this for you.

Avoid to insert too many parentheses, except if they calrify the mathematical meaning. In opposite to the clutter caused by unneeded parentheses, spaces would increase the readability massively. The elementwise multiplication .* is needed for arrays only. In your code it is applied exhaustively without a need, as far as I can see. This is not an error, but harder to read.

o  = b(2, :);
is = length(d);
L2 = 40e-3;
no = 1e-5;
pi = 22 / 7;   % A bad idea to redefing pi !!! Don't do this
a  = 4 * log(2);
e  = L2 / ii;
kt    = pi / 1550e-9 * no;
for i1 = 1:is
   x(i1) = 9.19 * (1 / d(i1) - 1e9 / 1550);
   k(i1) = @(z) pi / d(i1) * no * exp(-a * ((z - L2 / 2) / L2) ^ 2);

   g     = 0.98 * (4 * kt * exp(-kt * L2) + 0.15);
   q(i1) = @(z) sqrt(g - (1j .* x(i1)) ^ 2 + k(i1) ^ 2);
   dfdz{i1} = @(z, f) [ 1j * k(i1) * f(2) - (g - 1j * x(i1)) * f(1); ...
                       -1j * k(i1) * f(1) + (g - 1j * x(i1)) * f(2)];
   bc2{i1}   = @(fa, fb) [fa(1) - o(i1); fb(2)];
   finit{i1} = @(z) [(-1j / k(i1) * ((q(i1) * ...
           ((k(i1) * o(i1) / (x(i1) * tanh(L2 * q(i1)) + ...
           ... I gave up here
           g.*tanh(L2.*q(i1)).*1j - ...
           q(i1).*1j).*cosh((q(i1).*z)) + ...
           (-(k(i1).*o(i1).*tanh(L2.*q(i1)))./(x(i1).*tanh(L2.*q(i1)) + ...
           g.*tanh(L2*q(i1))*1j - ...
           q(i1).*1j).*sinh((q(i1).*z)))))+ ...
           ((g-(1j.*x(i1))).*((-(k(i1).*o(i1).*tanh(L2.*q(i1))) ./ ...
           (x(i1).*tanh(L2.*q(i1)) + g.*tanh(L2.*q(i1)).*1j - ...
           (q(i1).*1j)).*cosh(q(i1).*z)+ ...
           ((k(i1).*o(i1))./(x(i1).*tanh(L2.*q(i1)) + ...
           g.*tanh(L2.*q(i1)).*1j - ...
           q(i1).*1j).*sinh(q(i1).*z)))))))); ...
           (-(k(i1).*o(i1).*tanh(L2.*q(i1)))./(x(i1).*tanh(L2.*q(i1)) + ...
           g.*tanh(L2.*q(i1))*1j - ...
           q(i1).*1j).*cosh(q(i1).*z)) + ...
           ((k(i1).*o(i1))./(x(i1).*tanh(L2.*q(i1)) + ...
           (g.*tanh(L2.*q(i1)).*1j) - (q(i1).*1j)).*sinh(q(i1).*z))];
   solinit2(i1) = @(z) bvpinit(linspace(0,L2), finit{i1});
   sol2(i1)     = bvp4c(dfdz{i1}, bc2{i1}, solinit2(i1));
   idx2         = e:e:L2;
   u(:,i1)      = deval(sol2(i1), idx2(i1));
   delta2(i1)   = L2 .* x(i1);
   diff2(i1)    = d(i1) - 1550e-9;
end

[ayman elashmawy]

thanks for your reply

i think that the problem in the initial guess

can anyone help me to suggest a suitable guess to converge to a solution

[Walter Roberson]

If we had data to go on...

[John D'Errico]

We cannot know what problem you arre running into. That is because we have no data to go on, to test your code out.

And Jan is totally correct. Redefining pi to be 22/7 is a terrible idea. pi already exists in MATLAB. There is no need to define it as an incorrect value!!!!!!! All that does is start you out in trouble.

So even though you think the problem is the initial guess, that is not terribly relevant, since we lack any data tto use. How can we possibly know what a good initial guess would be for some totally complicated, problem, one where we see no data to base anything on?

Oh - there is no need to put the line:

dbstop if error

in the middle of your code. That will only slow it down. You can set dbstop ONCE if you want it turned on, before you ever run the code. That is entirely sufficient. But if your code is not generating errors, then it won't generate errors, and therefore, having dbstop turned on at all will only slow your code down.

Another obvious error:

e=l/ii;    

You use the variable ii but it is never defined.