Function call in ode45 does not work?

3 visualizzazioni (ultimi 30 giorni)
I G
I G il 27 Set 2019
Modificato: Alex Pedcenko il 27 Set 2019
I have function:
function [f,R]=fun_zap_ri_07(z,p)
beta=1;
ri=0.7;
R=ri-z.*(ri-1);
f=zeros(4,size(p,2));
f(1,:)=-32.*beta./(R.^4.*p(1,:));
f(2,:)=(-8*f(1,:)./R-f(1,:).*p(2,:))./p(1,:);
f(3,:)=(-p(2,:).*f(2,:)-8.*f(2,:)./R-8.*f(1,:)./(R.*R.*p(1,:))-f(1,:).*p(3,:))./p(1,:);
f(4,:)=(-f(2,:).*p(3,:)-f(3,:).*p(2,:)+8.*(-f(3,:)./R- (f(2,:)./p(1,:)-p(2,:).*f(1,:)./(p(1,:).*p(1,:)))./(R.*R)) -f(1,:).*p(4,:))./p(1,:);
which I am calling with
beta = 1;
z = linspace(1, 0, 101);
ri = 0.7;
R = ri - z .* (ri - 1);
[zv, pv] = ode45(@fun_zap_ri_07, z, [1; 0; 0; 0], options);
I need to put beta nad ri values in function definition, it means I need to have the same function as above, just with:
function [f,R]=fun_zap_ri_07_beta(z,p,beta,ri)
R=ri-z.*(ri-1);
f=zeros(4,size(p,2));
f(1,:)=-32.*beta./(R.^4.*p(1,:));
f(2,:)=(-8*f(1,:)./R-f(1,:).*p(2,:))./p(1,:);
f(3,:)=(-p(2,:).*f(2,:)-8.*f(2,:)./R-8.*f(1,:)./(R.*R.*p(1,:))-f(1,:).*p(3,:))./p(1,:);
f(4,:)=(-f(2,:).*p(3,:)-f(3,:).*p(2,:)+8.*(-f(3,:)./R- (f(2,:)./p(1,:)-p(2,:).*f(1,:)./(p(1,:).*p(1,:)))./(R.*R)) -f(1,:).*p(4,:))./p(1,:);
which I am calling with
z = linspace(1, 0, 101);
[zv, pv] = ode45(@fun_zap_ri_07_beta, z, [1; 0; 0; 0], 1, 0.7, options);
but it does not work. Error message is:
Undefined operator '-' for input arguments of type 'struct'.
Error in fun_zap_ri_07_beta (line 9)
R=ri-z.*(ri-1);
Error in odearguments (line 87)
f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.
Error in ode45 (line 113)
[neq, tspan, ntspan, next, t0, tfinal, tdir, y0, f0, odeArgs, odeFcn, ...

Risposte (1)

Alex Pedcenko
Alex Pedcenko il 27 Set 2019
Modificato: Alex Pedcenko il 27 Set 2019
it looks like there are not enough arguments to ode45
[t,y] = ode45(odefun,tspan,y0)
if you give odefun and all 4 inputs to your odefun, but not last 2 parameters tspan and y0, which are not passed to odefun.
It then "thinks" that tspan is your "options" and produces that error (options is "struct")

Categorie

Scopri di più su Programming in Help Center e File Exchange

Prodotti


Release

R2015a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by