euler function that you can reuse with different values?

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function [t, y, yprime]=euler(f,t0,tN,y0,N)
h=(tN-t0)/N;
t=t0:N:tN;
y=zeros(1,N+1);
yprime=f(t,y);
y(1)=y0;
t(1)=t0;
for i=1:N
t=(i-1)*h;
y(i)=y(i)+h*(f(y(i),t(i)));
end
end
this is my code for a euler method function. I cant seem to get it to run properly. Any ideas on what i am doing wrong. please help!
[SL: formatted function as code]
  3 Comments
Jacob Wood
Jacob Wood on 18 Feb 2020
It looks like you define f(t,y), but then when it is called inside the euler function it is called as f(y,t). Could that be a problem?
Benjamin Trivers
Benjamin Trivers on 18 Feb 2020
whenever, i take that part out the part in the yprime gets a red line under it and doesnt like it.

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Answers (1)

Srivardhan Gadila
Srivardhan Gadila on 25 Feb 2020
In your function euler, check for the following:
  1. In line 3 it should be "t=t0:h:tN;"
  2. In line 9 why are you changing the vector t to "(i-1)*h" ?
  3. In line 10 it should be "f(t(i), y(i))"
And for the function f:
f=@(t,y) (1/t.^2)-(y./t)-(y.^2);
Replace the (1/t.^2) with (1./t.^2) i.e., it should be:
f=@(t,y) (1./t.^2)-(y./t)-(y.^2);

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