MATLAB: Solution of coupled first order odes numerically

coupled odedsolveMATLABodeode45solve

eqn1 = coeff1*var1 + coeff2*diff(var1) + coeff3*var2 +coeff4*diff(var2) == 0;

eqn2 = coeff5*var1 + coeff6*diff(var1) + coeff7*var2 +coeff8*diff(var2) == 0;

bc1 = var1(0) == const1

bc2 = var2(0) == const2

i have all the coeffs defined as function handles. dsolve doesnt give solution as no explicit solution is present. How do i solve them numerically?

This can be easily done in Mathematica with NDSolve. However, i cant seem to think how i can appl oe45 or whatever is needed.

Best Answer

Use the mass matrix option of the ODE solvers.

Or explicitly solve your equations for diff(var1) and diff(var2) (2 linear equations in 2 unknowns).

Best wishes

Torsten.

Related Solutions

MATLAB: Solve ODE with BC

I doubt that your ode has an analytical solution - however here is a minimal working example of how to include BC's in a symbolic way:

 syms y(x)
 
 % Define first derivative for y
 Dy = diff(y,x);
 
 % Define differential equation
 ode = y == Dy * x;
  
 % Set conditions
 conds = [y(0)==0, y(1)==2, Dy(0)==2, Dy(1)==2];
 
 % Solve differential equation and display
 sol = dsolve(ode, conds)

If you dont find an analytical solution use bvp4c instead to solve numeric.

MATLAB: How to format this dsolve argument

syms y(x)
ode = x * diff(y, x) == 50 * x * diff(y, x, 2) - 40.3 * x + 101;
x_dot = dsolve(ode)

Best Answer

Related Solutions

MATLAB: Solve ODE with BC

MATLAB: How to format this dsolve argument

Related Question