`odeFunction`

Converts symbolic expressions into a numeric function handle for ODE solvers.

Category: Mathematics > Equation Solving

Syntax

f = odeFunction(expr, vars)

Returns a handle f(t, Y) that evaluates the vector expr for the state Y.

Description

odeFunction does for ODEs what matlabFunction does for plain expressions: it generates a numeric function in which the state variables become the entries of Y. Parameters that are symbolic variables become extra arguments after Y.

Input arguments

expr: Vector of symbolic expressions: the right-hand side of y' = expr.
vars: Vector of symbolic functions that make up the state, such as [x(t); y(t)].

Output arguments

f: Function handle with the signature f(t, Y) expected by ode45, returning a column vector.

Example

Harmonic oscillator right-hand side

syms x(t) y(t)
f = odeFunction([y; -x], [x; y]);
f(0, [1; 2])

Output

ans = 2×1

     2
    -1

Notes

Passing the output of odeToVectorField (whose state is written Y[1], Y[2]) is not accepted in MatLivre; pass the symbolic functions as vars instead.

odeFunction