Finite Differences: Central vs Forward Scheme

[member 428835]

Hi PF!

I am looking at finite differencing schemes and it seems we need more initial information to compute central finite differencing than forward finite differencing. Is this true, or am I understanding the process wrong?

Thanks!

 

[Khashishi]

In either case, you need three numbers, the values at two points and the distance between them. I don't see much difference between
$\frac{y_{n+1} - y_n}{\Delta x}$
$\frac{y_{n+1/2} - y_{n-1/2}}{\Delta x}$