daeFunction

Converts symbolic differential algebraic equations into a numeric residual function handle.

Category: Mathematics > Equation Solving

Syntax

f = daeFunction(eqs, vars)

Description

Each residual is the left side minus the right side of an equation, with the symbolic functions replaced by entries of y and their derivatives by entries of yp. The handle is the form expected by ode15i and decic, which solve fully implicit systems F(t, y, y') = 0.

Input arguments

eqs

Vector of symbolic equations of a DAE system.

vars

Vector of the unknown symbolic functions, such as [x(t) y(t)].

Output arguments

f

Function handle taking time t, the state vector y and its derivative yp, and returning a column of residuals.

Example

Residual of a small DAE

syms x(t) y(t)
eqs = [diff(x,t) == y, x^2 + y^2 == 1];
f = daeFunction(eqs, [x y]);
f(0, [1; 0], [2; 0])

ans = 2×1

     2
     0

See also

odeFunction massMatrixForm isLowIndexDAE ode15i decic