How can i define algebraic equation in differential function in MATLAB?

I want to solve 7 equations. I define all of them in one function in MATLAB dy=function(t,y) for example one of the equation is : dy(i,j)=(Ao*epsilonf.*Ucp*y(i,j))-(kg*Ao.*(y(1,1)-y(2,1))) now i should solve a algebraic equation in this function too.this is my algebraic equation: y(i,10)=((Deff/deltar)*(y(i,10)-y(i-1,10)))+kgAo*(y(2,10)-y(3,10)) how can i do this? i put a small coefficient that eliminate dy 10^-10* dy(i,10)= -y(i,10)+((Deff/deltar)*(y(i,10)-y(i-1,10)))+kgAo*(y(2,10)-y(3,10)) but matlab couldnt solve it. could you help me please?

Answer 1

[Torsten]

MATLAB's ODE solvers can account for systems which are a mixture of algebraic and differential equations.

Look at the example under

http://de.mathworks.com/help/matlab/math/ordinary-differential-equations.html#f1-670396

It should be easy to adapt it for your purpose.

Best wishes

Torsten.