deval

Evaluate the solution of a differential equation problem

Syntax

• sxint = deval(sol,xint)
  sxint = deval(xint,sol)
  sxint = deval(sol,xint,idx)
  sxint = deval(xint,sol,idx)
  

Description

sxint = deval(sol,xint) and sxint = deval(xint,sol) evaluate the solution of a differential equation problem. sol is a structure returned by one of these solvers:

• An initial value problem solver (ode45, ode23, ode113, ode15s, ode23s, ode23t, ode23tb),
• The delay differential equations solver (dde23),
• The boundary value problem solver (bvp4c).

xint is a point or a vector of points at which you want the solution. The elements of xint must be in the interval [sol.x(1),sol.x(end)]. For each i, sxint(:,i) is the solution at xint(i).

sxint = deval(sol,xint,idx) and sxint = deval(xint,sol,idx) evaluate as above but return only the solution components with indices listed in idx.

Example

This example solves the system using ode45, and evaluates and plots the first component of the solution at 100 points in the interval [0,20].

• sol = ode45(@vdp1,[0 20],[2 0]);
  x = linspace(0,20,100);
  y = deval(sol,x,1);
  plot(x,y);