Matlab problem for implicit differential equation

[oby7842]

I am trying to solve set of implicit differential equations. But first...i need to find out the consistent initial conditions for my problem( initial condition for derivative). that's why i am using 'decic' built-in function of matlab. But facing following problem. My set of differential equations function is :

function res=sample(t,z,zdot)


res=0;

res=[zdot(1);zdot(2)]-[z(2); -1.96*sin(z(1))];



script file from which I am running 'decic' function is as follows:



clc;

clear;


tspan=[0:2:20];

z0=[1;0];

t0=[0;0];

zdot0=[0;0];

[z0,zdot0]=decic('sample',t0,z0,1,zdot0,0)



but I am getting following error message:



? Error using ==> decic at 45
Cannot specify more than 2 components of y0 and yp0.

Error in ==> solver_sample at 8
[z0,zdot0]=decic('sample',t0,z0,1,zdot0,0)

Can't I solve consistent initial condition's with decic function??

I will appreciate any help regarding this. thanks for reading my problem.

regards
Omar

 

[Vailanor]

Yes, you can solve consistent initial conditions with the decic function. It looks like you have too many components in your z0 and zdot0 vectors. The decic function expects 2 components for each of these vectors, so make sure that you are only providing 2 components for each.