**Introduction**

On this page you will find links to various
problems from Dr. Watkins excellent book. This book is a very nice
introduction to numerical linear algebra. It is quite enjoyable
to read and has a very nice set of problems to work. I have begun
to LaTeX solutions to the problems from the *second*
edition and what I have been able to do are presented below. Note
currently due to time restrictions I have not been able to LaTeX
all that I would have like. As I get more time I will be continually adding
solutions. This is a work in progress. While of lesser value, I
have also included my scanned solutions to many of the problems from
the first edition.

**Second Edition Solutions Manual**- My original handwritten notes from the first edition (of more limited value)

- rco_forward_sub.m (recursive column oriented forward substitution)

- test_rco_forward_sub.m (testing code for rco_forward_sub.m)

- exercise_1_1_9.m (timings of matrix vector multiplication)

- exercise_1_1_10.m (further timings of matrix vector multiplication)

- exercise_1_1_11: (BLAS2 FORTRAN and C version of matrix vector multiplication)

- exercise_1_1_14.m (timings of matrix multiplication)

- exercise_1_2_7.m (numerical solution for circuit voltages)

- exercise_1_2_9.m (numerical solution for circuit currents)

- exercise_1_2_11.m (numerical solution for the cart displacements)

- exercise_1_3_22 (FORTRAN routines for solving triangular systems A in Ax=b):
- exercise_1_4_23.m (using the Cholesky decomposition to test for positive definiteness)

- exercise_1_6_3.m (visualizing sparse Cholesky factorizations)

- exercise_1_6_4.m (visualizing sparse Cholesky factorizations on the delsq matrix)

- exercise_1_6_5.m (visualizing sparse Cholesky factorizations on the airfoil matrix)

- exercise_1_6_6.m (visualizing various unknown orderings on a finite element matrix (wathen))

- exercise_1_8_10.m (simple experiments with Matlab lu command)

- condif.m (generates the coefficient matrix for a discretization of the 1d convection-diffusion equation)

- exercise_1_8_22 (routines for performing Gaussian elimination with partial pivoting):
- For pedagogical purposes, direct implementations of the solution routines from the book are given below
- A Matlab implementation: splu.m (Gaussian elimination with partial pivoting)

- A Matlab implementation: splu.m (Gaussian elimination with partial pivoting)

**Chapter 2 (Sensitivity of Linear Systems):**

**Chapter 7 (Iterative Methods for Linear Systems):**

- For pedagogical purposes, direct implementations of the solution routines from the book are given below

John Weatherwax Last modified: Thu Jul 26 09:15:18 EDT 2007