Cpp, Numerical Methods, Programming.
languages/packages in the past. The beauty of this problem is that it really tests the performance of array views, delayed evaluation and slicing/broadcasting when there is aliasing. In NumPy, the code looks something like this: u[1:-1, 1:-1] = ((u[0:-2, 1:-1] + u[2: , 1:-1] + u[1:-1, 0:-2] +