error ''The function might be unused''

I am trying to call a function 'Fung' but MatLab cannot read. it gives me an error 'The function Fung might be unused'. Any help would be greatly appreciated.

 Function mainprogram
  ...
  model='Fung';
  iniconstants=[1 0.1 0.1 0.1];
  RadLambexp=[riexp lambdaexp];
   ...
 end 

function[Pt,Ft]=PF(c,RadLamb,Ro,Ri,theta0,ksi,w,model)
ri=RadLamb(:,1);
lambda=RadLamb(:,2);
P=zeros(length(ri),1); 
F=zeros(length(ri),1); 
ro=sqrt((Ro.^2-Ri.^2)./pi.*lambda.*theta0+ri.^2);

for i=1:length(ksi)
    r=(ro+ri)./2+(ro-ri)./2.*ksi(i);
    R=sqrt(Ri.^2+(((pi.*lambda)./theta0).*(r.^2-ri.^2)));
    Ezz=0.5*((lambda.^2)-1);
    Ett=0.5*(((pi.*r)./(theta0.*R).^2)-1);
    calcPartials=str2func(model);
    [dWtt,dWzz]=calcPartials(c,Ett,Ezz);
    P=P+w(i).*((((pi.*r)./(theta0.*R)).^2).*dWtt)./r;
    F=F+w(i).*(2.*lambda.^2.*dWzz-((pi.*r)./(theta0.*R)).^2.*dWtt).*r;
end
Pt=((ro-ri)./2).*P; 
Ft=pi.*((ro-ri)./2).*F; 
end

function[dWtt,dWzz]=Fung(c,Ett,Ezz)
dWtt=(c(1).*(c(2).*Ett+c(4).*Ezz)).*(exp(c(2).*Ett.^2+c(3).*Ezz.^2+2.*c(4).*Ett.*Ezz));
dWzz=(c(1).*(c(3).*Ezz+c(4).*Ett)).*(exp(c(2).*Ett.^2+c(3).*Ezz.^2+2.*c(4).*Ett.*Ezz));
end

[David Young]

Where is the call to Fung? I don't think there is one in the code you show, so that's why you get the warning that it appears to be unused.

If there's a call to Fung somewhere in your main program, the problem may be that Fung needs to be in its own m-file, called Fung.m, and not in the same file as PF. Is that the case?

Answer 1

[Walter Roberson]

That is a warning, not an error.

What I advise is that you replace

calcPartials=str2func(model);

with

calcPartials = model;

and that in the main function you replace

model='Fung';

with

model = @Fung;