How to solve an ODE with ode45 in a parfor loop?
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I have the following code:
function [t,S] = solve_ode(fg_vars,tspan)
inital_conds = [0 0];
t = zeros(65,1);
S = zeros(65,2);
parfor i = 1:100
[t(:,i), S(:,i)] = ode45(@(t,s) fn(t,s,fg_vars),tspan,inital_conds)
end
t = t(:)
S = S(:)
end
Which gives me the following error:
Unable to perform assignment because the size of the left side is 65-by-1 and the size of the right side is 65-by-2.
I dont understand why this error occures, because when I try to calculate the ODE without the pafor loop, the produced solutions are of this size:
t = 65x1 double
S = 65x2 double
Thanks!
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Answers (1)
KSSV
on 29 Oct 2020
Edited: KSSV
on 29 Oct 2020
[t(:,i), S(:,i)] = ode45(@(t,s) fn(t,s,fg_vars),tspan,inital_conds)
In the above t will be a column vector and S will be a column matrix with two columns. You cannot save like that. You can do
T = cell(100,1) ;
S = cell(100,1) ;
for i = 1:100
[t, s] = ode45(@(t,s) fn(t,s,fg_vars),tspan,inital_conds) ;
T{i} = t ;
S{i} = s ;
end
The above cannot be used with parfor...you cannot index the parfor loop.
7 Comments
KSSV
on 29 Oct 2020
Did you notice there is s and S. The one which is saved are initialized as cell S. And s is saved into S. You should have messed up with this.
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