Question: 02-01-2010: What is the due date? How should I submit it?
Answer: This assignment is due at 4:00pm on Monday, February 15. Late penalties begin at 4:01. There are two acceptable ways to submit it: (1) Give it to me in the classroom, before class begins. (2) Deliver it to my office, any time prior to when I leave for class on the due date. (Slide it under the door if I am not there.) Do not put it in my mailbox, and do not leave it in my office after I leave for class on the due date. Email submission is acceptable only in "emergencies".
Question: 02-01-2010: What are the point values for the challenges?
Answer: 45 points total.
Challenge 1 : 6 points.
Challenge 2 : 10 points for correctness and 5 for documentation.
Challenge 3 : 5 points for correctness and 4 for documentation.
Challenge 4 : 6 points for the experiment and 9 for the discussion.
Question: 02-01-2010: What should I submit?
Answer: I grade everyone's Challenge 1, then everyone's 2, etc., to help insure uniformity in grading, so I would really appreciate your help in making this easy.
Grading notes:Question: 02-01-2010: How do I get started?
Answer: My advice is to read Chapter 23 and run the programs there on the new test problem (in Challenge 4). If you do this by the end of the first weekend, you are probably on track to finish the homework on time.
Question: 02-01-2010: The finite difference solution is only defined at the mesh points. How do I extend it to other points?
Answer: Use piecewise linear interpolation. In other words, if x is between the j-th and (j+1)-st mesh points, then set the value of u at x to be u(j)*(x-x(j))/(x(j+1)-x(j)) + u(j+1)*(x(j+1)-x)/(x(j+1)-x(j)) Correction, 02-16-2010. This should say u(j+1)*(x-x(j))/(x(j+1)-x(j)) + u(j)*(x(j+1)-x)/(x(j+1)-x(j))
Question: 02-05-2010: In Problem 4, a(x) and c(x) are listed, but what is f(x)?
Answer: You are given a, c, and the true solution u. Calculate f from these, either by hand or, if you find it easier, with the help of Matlab's symbolic computation features.
Question: 02-11-2010: In the matrix and right-hand side submission for problems 2 and 3, how many mesh points should we use?
Answer: Use 3 points per subinterval. (I've made this addendum in red, up above.)
Question: 02-16-2010: I had a question regarding something you mentioned in class yesterday. I think you numbered the mesh points as x0 , x1, x2, .., xm which gives h = 1/M.) But numbering them as x1, x2, x3, ..., xm gives h = 1/(M-1). Which numbering is used in the homework?
Answer: Yes, there is a difference in notation. Larson&Thomee p.43 number the mesh points starting with x_0, and that is the notation used in Part 2 of the notes.
Chapter 23 and your homework challenges number the mesh points starting from x_1.
Question: 02-19-10:
Answer: Is it ok to modify axlin in addition to fe_linear?
Question: Yes, you can modify any function you want.
Answer: