Hi all,
I'd like to apply Matlab Coder to an 'ode45' function used with extra parameters. My problem is that Matlab coder does not support anonymous function so I tried to use persistent variable instead. But I obtain an error message.
Do you know where is the mistake in my code or what is the best implementation strategy for this case?
- As a benchmark, from the Matlab help, it is possible to modify the ‘rigid’ example and to use anonymous function (although there is no meaning here). It works. See section a)
- But I obtain an error message with the following code when I use persistent variable instead. See section b)
a) Code with anonymous function: no problem
VarAdd = 0.1;
options = odeset('RelTol',1e-4,'AbsTol',[1e-4 1e-4 1e-5]);
[T,Y] = ode45(@(t,y) rigid2(t,y,VarAdd),[0 12],[0 1 1],options);
plot(T,Y(:,1),'-',T,Y(:,2),'-.',T,Y(:,3),'.')
function dy = rigid2(t,y,VarAdd)
dy = zeros(3,1);
dy(1) = y(2) * y(3) + VarAdd;
dy(2) = -y(1) * y(3) + VarAdd;
dy(3) = -0.51 * y(1) * y(2) + VarAdd;
b) Code with persistent variable: problem
Script:
VarAdd = 0.1;
t = [0 12];
y = [0 1 1];
[ T,Y ] = rigidp(t, y, VarAdd);
plot(T,Y(:,1),'-',T,Y(:,2),'-.',T,Y(:,3),'.')
Function #1
function [ T,Y ] = rigidp(t, y, VarAdd)
persistent VarAdd2;
VarAdd2 = VarAdd;
rigidp2(t,y,VarAdd2);
options = odeset('RelTol',1e-4,'AbsTol',[1e-4 1e-4 1e-5]);
[T,Y] = ode45(@rigidp2, t, y, options);
end
Function #2
function dy = rigidp2(t, y, VarAdd2)
dy = zeros(3,1);
dy(1) = y(2) * y(3) + VarAdd2;
dy(2) = -y(1) * y(3) + VarAdd2;
dy(3) = -0.51 * y(1) * y(2) + VarAdd2;
Here is the error message:
Error using rigidp2 (line 5)
Not enough input arguments.
Thanks.
Nicolas
