This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: CS 240A: Applied Parallel Computing // Homework 3 Assigned April 12, 2010 Due by 11:59pm Monday, April 26 You may do this homework in groups of twoin fact, I prefer that you do so. You may form groups however you want, but I encourage groups that have students from two different departments. The object of this problem is to write a parallel program, using MPI, to use conjugate gradients (CG) to solve the finite difference discretization of Poissons equation in two dimensions on a regular square grid of n = k 2 points. (This is also known as the model problem.) If we write the discretized problem as Ax = b , then A is the sparse nby n matrix (whose nonzeros are all 4s and 1s) representing the discretized operator. For this homework, you will not generate or store any of A explicitly. b is an nvector containing the boundary conditions and any forcing terms. You will write a routine to generate b for debugging, and we will write one for testing and grading. x is an nvector giving the answer. The CG algorithm is outlined in the course slides for April 7 and April 12, and is described in detail in the references on the course resources page. There is a sequential Matlab code for CG linked to the course web page under Homework 3. You will need to write three routines: DAXPY (which adds a scalar multiple of one dense vector to another, y = y + z ); DDOT (which computes the inner, or dot, product of two dense vectors,...
View
Full
Document
This note was uploaded on 12/27/2011 for the course CMPSC 240A taught by Professor Gilbert during the Fall '09 term at UCSB.
 Fall '09
 GILBERT

Click to edit the document details