Euler's method

Hello,

Where is the problem? Can you look at it?

h=0.25;

a=1; %start

b=2; %end

n=5; %iteration number

x=zeros(n,1);

y=zeros(n,1);

x=linspace(a,b,n);

y(1)=2;

for i= 1:n-1

y(i+1)=y(i)+ h*(((sin(2*x))/x^2)-(2*y/x));

end

[x y]

Unable to perform assignment because the left and right sides have a different number of

elements.

Error in foo (line 16)

y(i+1)=y(i)+ h.*(((sin(2.*x))./x.^2)-(2.*y./x));

Answer 1

[Wan Ji]

Hi,

Use

y(i+1)=y(i)+ h*(((sin(2*x(i)))/x(i)^2)-(2*y(i)/x(i)));

instead of

y(i+1)=y(i)+ h*(((sin(2*x))/x^2)-(2*y/x));

[Ahmet Akcura]

Again there is an errror;

Error using horzcat

Dimensions of arrays being concatenated are not consistent.

Error in foo (line 18)

[x y]

[Wan Ji]

@Ahmet Akcura Hi,

Your x array is not transposed, its size 1 by n while y array is n by 1. So I transpose it for you.

h=0.25;
a=1; %start
b=2; %end
n=5; %iteration number
y=zeros(n,1);
x=linspace(a,b,n)';
y(1)=2;
for i= 1:n-1
    y(i+1)=y(i)+ h*(((sin(2*x(i)))/x(i)^2)-(2*y(i)/x(i)));
end
[x y]
plot(x,y,'r-o') % plot the result
xlabel('x'); ylabel('y')