Euler Method IVP Coding Help

I have an IVP problem I'm trying to solve with Euler's Method. The problem is: dy/dx = 1-x+1, y(0) = 1. My time step is 0.01 and my x final is 3. I get an "Index exceeds matrix dimensions." error when I try and run the code. Where am I going wrong? Here is my code:

 clear; clc;
%inputs
xo=input('Enter x initial: ');
yo=input('Enter y initial: ');
dx=input('Enter delta x (time step): ');
xf=input('Enter x final: ');
x(1)=xo;
y(1)=yo;
n=1;
% function [out] = Euler(x,y)
% out=1-x+y;
% end
while x(n)<=xf
    y(n+1)=y(n)+Euler(x(n),y(n))*(dx);
    n=n+1;
end

Answer 1

[Aquatris]

Your x vector only has a single element in it. After while loop goes once, it tries to reach x(2), which does not exist. That is why you are getting index exceeds error.

Answer 2

[John]

w0=0.5;

a=0;

b=2;

hh=[0.5 0.2 0.1 0.05 0.01 0.005 0.001];

f=@(t,y) y-t^2+1;

for j=1:7

we(1,j)=w0;

wm(1,j)=w0;

wr(1,j)=w0;

h=hh(j);

n=(b-a)/h;

for i=1:n

t=(i-1)*h;

we(i+1,j)=we(i,j)+h*f(t,we(i,j));

wm(i+1,j)=wm(i,j)+h*f(t+h/2,wm(i,j)+(h/2)*f(t,wm(i,j)));

k1=h*f(t,wr(i,j));

k2=h*f(t+h/2,wr(i,j)+k1/2);

k3=h*f(t+h/2,wr(i,j)+k2/2);

k4=h*f(t+h,wr(i,j)+k3);

wr(i+1,j)=wr(i,j)+(1/6)*(k1+2*k2+2*k3+k4);

end

error_we(j)=abs(we(n+1,j)-y(2));

error_wm(j)=abs(wm(n+1,j)-y(2));

error_wr(j)=abs(wr(n+1,j)-y(2));

end

% y=@(t)....

t=a:h(3):b;

plot(t,y(t),)