Euler, Runge Kutta, and ODE45

Hi so i have to create a program capable of pick the function that the user wants to utiliezed, if user wants to calculate the function base using euler method the program will select Eulers Method and so on. I know how to excute them all in different mfiles but im not sure how to put them all in one mfile. I also need another mfile where all the constant are gonna be

%RK 4TH ORDER

for j=1:n

k1=f3(x(j),y2(j));

k2=f3(x(j)+0.125,y2(j)+k1*0.125);

k3=f3(x(j)+0.125,y2(j)+k2*0.125);

k4=f3(x(j)+0.125,y2(j)+k3*0.125);

y2(j+1)=y2(j)+(0.25/6)*(k1+2*(k2+k3)+k4);

x(j+1)=x(j)+h;

end

%EULERS METHOD

for i=1:n

y(i+1)=y(i)+0.25*f1(x(i),y(i));

x(i+1)=x(i)+0.25;

end

%ODE_45

fun=@(t,y)y*(t^2-1.1)

[t,y]=ode45(fun,[0 2],1)

[James Tursa]

Your RK4 code has an error. This line:

k4=f3(x(j)+0.125,y2(j)+k3*0.125);

should be this

k4=f3(x(j)+0.25,y2(j)+k3*0.25);

Answer 1

[James Tursa]

You could use a switch control block to run the method selected.

https://www.mathworks.com/help/matlab/ref/switch.html?s_tid=srchtitle