1. The OutputFcn should have the format
status = myfun(t,y,flag)
but your anonymous function takes a single input (status). Try
options = odeset('OutputFcn',@RotorOut);
2. Perhaps it is hidden in the ellipses, but you don't seem to declare rs as global in QR_solver().
Note, however, that the time points at which the output from ode45 is returned may be different from the points at which the functions themselves are evaluated. So if you want to save intermediate results for later use, you will probably have to interpolate afterward, or just loop through the ode45 output and recompute the intermediate results.
I definitely wish there were a way to have ode45 compute auxiliary outputs!
A somewhat cleaner way to share the data between QR_solver() and RotorOut() would be to use nested functions:
[ode, out] = getHandles();
options = odeset('OutputFcn',@(status)RotorOut(t,y,flag));
[t,y] = ode45(@QR_solver,delt,y0,options,[],D);
function [ode, out] = getHandles()
ode = @QR_solver;
out = @RotorOut;
rs = []; % make this variable shared
function dydt = QR_solver(t,y,D)
...
rs = XX;
...
end
---
function status = RotorOut(t,y,flag)
if flag ~= strcmp(flag,'init')|strcmp(flag,'done')
rotspeed = evalin('base','rotspeed');
k = k + 1;
rotspeed(k) = rs;
assignin('base','rotspeed',rotspeed)
status = 0;
end
t % just to verify the function is being called
end
end
