MATLAB Mathematics - SERC - Index of

Initial Value Problems for DDEs
For more advanced applications, you can specify solver options by passing an
input argument options.
options
Structure of optional parameters that change the default
integration properties. You can create the structure options
using odeset. The odeset reference page describes the
properties you can specify.
The output argument sol is a structure created by the solver. It has fields:
sol.x
Nodes of the mesh selected by dde23
sol.y Approximation to yt () at the mesh points of sol.x
sol.yp Approximation to y′ () t at the mesh points of sol.x
sol.solver 'dde23'
To evaluate the numerical solution at any point from [t0,tf], use deval with
the output structure sol as its input.
Solving DDE Problems
This section uses an example to describe:
• Using dde23 to solve initial value problems (IVPs) for delay differential
equations (DDEs)
• Evaluating the solution at specific points
Example: A Straightforward Problem
This example illustrates the straightforward formulation, computation, and
display of the solution of a system of DDEs with constant delays. The history
is constant, which is often the case. The differential equations are
y 1 ′() t = y 1 ( t – 1)
y 2 ′() t = y 1 ( t – 1) + y 2 ( t – 0.2)
y 3 ′() t = y 2 () t
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