calling a function from a script

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Ilias Minas
Ilias Minas on 18 Dec 2021
Commented: Torsten on 19 Dec 2021
Hi all,
I have a differential equation which I want to solve using Euler method.
I created a script which has only the equation:
function dx=differential (t,x);
dx/dt=-x+1/(1+exp(-5*(x-1)));
end
And another script in order to implement Euler's method
f = input('differential.m'); % Enter the function right to the ODE
t0 = input ('Enter initial value of time'); % Value that time starts
x0 = input ('Enter initial value of x'); % Initial condition
tn = input ('End point of time'); % Value that time ends
h = input ('Enter step size'); % TIme step value
% Euler method & Initial conditions
t(1)= t0;
x(1)= x0;
% Euler Loop
for i=1:n
x(i+1) = x(i) + h*f(t(i),x(i));
t(i+1) = t0 + i*h;
end
I want when I press play to the script of Euler's solution, instead of putting the differential equation manually, to call it direclty from the script which includes the equation.
How can I do this, and in which form should the equation be written in order to achieve this?
Thank you very much
Yours sincerely
Ilias Minas

Accepted Answer

Geoff Hayes
Geoff Hayes on 18 Dec 2021
@Ilias Minas - can't you just replace f with differential like
t0 = input ('Enter initial value of time'); % Value that time starts
x0 = input ('Enter initial value of x'); % Initial condition
tn = input ('End point of time'); % Value that time ends
h = input ('Enter step size'); % TIme step value
% Euler method & Initial conditions
t(1)= t0;
x(1)= x0;
% Euler Loop
for i=1:n
x(i+1) = x(i) + h*differential(t(i),x(i));
t(i+1) = t0 + i*h;
end
  4 Comments
Torsten
Torsten on 19 Dec 2021
function dx = differential (t,x);
dx = -x+1/(1+exp(-5*(x-1)));
end

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