MATLAB Mathematics - SERC - Index of

5 Differential Equations
For example, to change the value of the relative error tolerance of the solver
from the default value of 1e-3 to 1e-4,
1 Create an options structure using the function odeset by entering
options = odeset('RelTol', 1e-4);
2 Pass the options structure to the solver as follows:
- For all solvers except ode15i, use the syntax
[t,y] = solver(odefun,tspan,y0,options)
- For ode15i, use the syntax
[t,y] = ode15i(odefun,tspan,y0,yp0,options)
For an example that uses the options structure, see “Example: Stiff Problem
(van der Pol Equation)” on page 5-20. For a complete description of the
available options, see the reference page for odeset.
Examples: Applying the ODE Initial Value Problem
Solvers
This section contains several examples that illustrate the kinds of problems
you can solve. For each example, there is a corresponding M-file, included in
MATLAB. You can
• View the M-file code in an editor by entering edit followed by the name of
the M-file at the MATLAB prompt. For example, to view the code for the
simple nonstiff problem example, enter
edit rigidode
Alternatively, if you are reading this in the MATLAB Help Browser, you can
click the name of the M-file in the list below.
• Run the example by entering the name of the M-file at the MATLAB prompt.
This section presents the following examples:
• Simple nonstiff problem (rigidode)
• Stiff problem (vdpode)
• Finite element discretization (fem1ode)
5-18