Cheg 258 - Lecture Notes - Jan. 25, 1999

Announcements

• The Matlab tutorial will be held today (and all following mondays) in room 131, Debartolo from 6:00 - 7:30PM.

Class notes

The main points of the lecture were

• PLU Factorization

Goals:

• Factor a matrix into the product of upper triangular, lower triangular, and pivoting matrices.
• Use PLU decomposition to solve systems of equations.

Reading

• The class notes, Ch. 2 of Hanna, and Ch. 3 of Kahaner.
  
  
• Print out the matlab documentation of the '\' command from the online reference documentation. You can find this under the cheg258 home page. Click on matlab help, then on 'ops' under the categories of functions, and then on '\'

Questions of the Day

• Does pivoting change the physical problem being solved by Gaussian Elimination?
• What criteria would you use to reorder equations in pivoting?
• We have looked at row pivoting. Is there another way to overcome the same problem? What does it physically correspond to?

Matlab Example Codes

example 6