Assignment 2

Anyone else battling to understand the ADI method?

Does anyone have a decent resource for this?

Hey sheepapple
I'm only working on this assignment now and I'm a bit lost. I haven't even got to the ADI method - sorry!
I'm a bit confused at the size of the plate and the distance between the x and y values in question 2 though. Using 3cm, the points on the diagram in the question do not align with the nodes. Am I missing something?

Ok I have just had a look at ADI and I think I understand it, but I have no idea how to write the code for it yet.
The problem is that your formulae only set up a matrix that then needs to be solved by Gaussian elimination.

There is a lecture on it here: http://www.youtube.com/watch?v=Y4CYG9kr2mM

Thanks Rory. Let me watch that video this morning and see. Will post thereafter.

Alright Rory. I've watched it stop-start between work etc. I think I have an idea of how this works on pen/paper. The gaussian elimination part is a pain but in Matlab you use the rref command to facilitate this. Unpleasant anyways though.

It looks like writing this program is going to be a real pain in the butt.

Regarding question 2, you have a 12 x 15 cm plate. When you break it up into a 3cm mesh, you get a 4 x 5 grid. I managed to solve this sucessfully I think. If you get stuck I can try help you further - I don't mind.

Let me try write the program for question 3 and I will check in again soon (probably after lunch).

I'm not closer to a solution now than I was 4 hours ago.

I have generated the a tridiagonal matrix A, however what do you multiply it with to get b? I make reference to the document Dr Moremedi put together.

Hi
I eventually gave up on question 3. It was taking me too long and I wasn't making any progress.
It's frustrating because it was something that was quite doable by hand - very hard program though!

Yeah. It's extremely frustrating. I now kind of have an idea of how it works, but to program is an absolute nightmare!

My answers for 1 and 2 are in rough and tonight I will copy them neatly. If I have spare time after supper I will work on question 3 some more.

Regarding question 3 i generated the tridiagonal row traversal matrix and multiplied it by the row vector. I need to now generate the tridiagonal column traversal matrix and multiply by the column vector. I am battling with this part now!