I have big problem with finite difference schemes (DS) on Matlab. I need write DS on Matlab, example:
u_x=(u_(i+1,j)-u_(i-1,j))/2, we choose step is 1.
On Matlab:
u_x=(u( :,[2:n,n])-u( :,[1,1:n-1]))/2
And I can write u_y, u_xx, u_yy, u_xy. But now, I need to write for higher order, example...