Figure Properties - SERC

odefile
2odefile
Purpose Define a differential equation problem for ordinary differential equation (ODE)
solvers
Note This reference page describes the odefile and the syntax of the ODE
solvers used in MATLAB, Version 5. MATLAB, Version 6, supports the
odefile for backward compatibility, however the new solver syntax does not
use an ODE file. New functionality is available only with the new syntax. For
information about the new syntax, see odeset or any of the ODE solvers.
Description odefile is not a command or function. It is a help entry that describes how to
create an M-file defining the system of equations to be solved. This definition
is the first step in using any of the MATLAB ODE solvers. In MATLAB
documentation, this M-file is referred to as an odefile, although you can give
your M-file any name you like.
You can use the odefile M-file to define a system of differential equations in
one of these forms
or
where:
y′ = ft ( , y)
Mt ( , y)y′
= ft ( , y)v
t is a scalar independent variable, typically representing time.
y is a vector of dependent variables.
f is a function of t and y returning a column vector the same length as y.
Mt ( , y)
is a time-and-state-dependent mass matrix.
The ODE file must accept the arguments t and y, although it does not have to
use them. By default, the ODE file must return a column vector the same
length as y.
All of the solvers of the ODE suite can solve Mt ( , y)y′
=
ft ( , y)
, except ode23s,
which can only solve problems with constant mass matrices. The ode15s and
2-1559